T 0493/23 17-01-2025

Main request (auxiliary request 11 underlying the decision under appeal) - added subject-matter (Article 123(2) EPC)

1. It was common ground between the parties that the chamfered surfaces of feature 1.8 were only disclosed in the application as filed in the context of the drawings and the detailed description of paragraphs [0039] to [0042] (see the English translation of the PCT-application filed upon Entry into the Regional Phase). By adding feature 1.8 to claim 1, the respondents thus limited the claimed threaded connection by a feature taken from a specific embodiment. The text in paragraphs [0039] and [0040] essentially corresponds to the wording of feature 1.8. The issue under dispute was whether the additional features disclosed in paragraphs [0041] and [0042] and in the drawings of the application as filed are inextricably linked to feature 1.8 so that their omission from claim 1 would result in an unallowable intermediate generalisation.

2. In the appellant's view, the question should be answered in the affirmative. The relative position of load flanks and stab flanks was not described as optional in paragraphs [0041] and [0042] of the application as filed. The fact that the chamfered surfaces were optional features did not mean that any additional features that were realised in case the chamfered surfaces were present were themselves optional.

3. The respondents disagreed and pointed out that the chamfered surfaces and the additional features are in separate paragraphs of the application as filed. There was no link between a state of contact or non-contact in respect of the various thread flanks and thread crests and roots, on the one hand, and the presence of chamfered surfaces, on the other hand. The chamfers had no bearing on how the various surfaces of the threads interacted.

4. Although the chamfered surfaces are described as optional features in paragraph [0039] ("preferably"), the board sees no ambiguity in the disclosure of paragraph [0041] that, in the event the male and female threads comprise chamfered surfaces ("If the male and female threads 11 and 21 include chamfered surfaces 11e and 21e, [...]"), they are not in contact with each other in the constant-thread-width portions. The word "either" at the end of the sentence refers to the previous sentence, according to which the stab flanks are not in contact with each other. The conditional clause in paragraph [0042], in turn, clearly discloses that, in the event the male and female threads comprise chamfered surfaces, they are in contact with each other in the varying-thread-width portions. In the same paragraph, the stab flanks (and the load flanks) are also described in contact with each other. The drawings clearly disclose these additional features: Figure 2A illustrates a gap between the stab flanks 11c, 21c and between the chamfers 11e, 21e in the constant-thread-width portions, Figure 2B shows that there is no such gap in the varying-thread-width portions. No alternative arrangement of the stab flanks or the chamfered surfaces is disclosed in the context of this specific embodiment of the application as filed. The board is therefore not persuaded that feature 1.8 of claim 1 is not closely related to the additional features disclosed in paragraphs [0041] and [0042] of the application as filed.

5. The respondents argued that paragraphs [0039] and [0040], on the one hand, and paragraphs [0041] and [0042], on the other hand, could be decoupled because they were concerned with different aspects of the embodiment. The board disagrees. The chamfered surfaces are defined in feature 1.8 and in paragraph [0039] of the application as filed as inclined surfaces connecting a stab flank and a thread root. These are depicted in Figures 2A and 2B of the application as filed as slanted lines 11e and 21e bevelling off a corner of the (cross-sectional view of the) male or female thread. As such, the chamfers shape the surface of both the male thread and the female thread. Through the conditional clauses in paragraphs [0041] and [0042], the application as filed expresses the requirement that a threaded connection with male and female threads having the shape as defined in paragraphs [0039] and [0040] must have the additional features of contact and non-contact in the different portions. Even if it were theoretically possible for the respective stab flanks of male and female threads to make contact in the varying-thread-width portions while preserving a gap between the chamfered surfaces, such an option would be at variance with the straightforward disclosure of paragraph [0042].

6. No other passage of the description of the application as filed indicates that the additional features paragraphs [0041] and [0042] can be considered optional in the embodiment shown in Figures 2A and 2B. The respondents have referred to Figures 3 and 6. But Figure 6 is depicted as part of a "second embodiment". Regarding Figure 3, the appellant convincingly argued that it shows a larger structure of the first embodiment with the aim to highlight the variations in the maximum and minimum thread-groove widths ("W11min", "W21max"). It cannot be concluded from this drawing that what is specifically described in the context of Figures 2A and 2B is no longer mandatory.

7. Also with regard to the functions of feature 1.8 and the additional features of paragraphs [0041] and [0042] the respondents have not persuaded the board. It may very well be that chamfered surfaces reduce the stress on the teeth of the male and female threads. But through their contact in the varying-thread-width portions (and lack of contact in the constant-thread-width portions), it stands to reason that the chamfered surfaces also influence the torque build-up and the sealing performance when the threaded connection is made up.

8. It follows from the above that, by adding feature 1.8 but omitting the additional features disclosed in paragraphs [0041] and [0042] of the application as filed from claim 1 of the respondents' main request, the claim has been amended in such a way that it contains subject-matter which extends beyond the content of the application as filed (Article 123(2) EPC). The respondents' main request is thus not allowable.

Twelfth auxiliary request

9. After withdrawal of the first to eleventh auxiliary requests at the oral proceedings held before the board, the twelfth auxiliary request was the respondents' next request to be considered. The claims of the twelfth auxiliary request were filed for the first time in reply to the statement of grounds of appeal.

(a) Admittance

10. The appellant requested not to admit the twelfth auxiliary request in the appeal proceedings. Its case was essentially that the request could and should have been filed already during the proceedings before the opposition division, especially in view of the appellant's objections against the claims of then auxiliary request 5 raised in the letter dated 22 July 2022.

11. The board notes that the passage on pages 6 and 7 of that letter, to which the appellant referred, objects against an amendment consisting in isolating features from paragraphs [0041] and [0042] of the application as filed. However, the objection was not directed to the addition of chamfered surfaces to claim 1. Claim 1 of what was then auxiliary request 5 did not define any chamfered surfaces. In fact, the only other issue with Article 123(2) EPC the appellant seemed to have had was against claim 1 of then auxiliary request 2 also filed in reply to the notice of opposition, albeit for the reason that the geometrical features of paragraphs [0037] and [0038] were missing (see page 5 of the letter dated 22 July 2022). Moreover, the opposition division had not seen any issue with Article 123(2) EPC at all in the communication sent in annex to the summons for the oral proceedings.

12. It was only at the oral proceedings held before the opposition division that the appellant raised an objection of added subject-matter against feature 1.8 of claim 1 of auxiliary request 11 arguing an intermediate generalisation in respect of paragraph [0041] and [0042] of the application as filed (see point 25 of the reasons for the decision under appeal). Filing of the twelfth auxiliary request with the reply to the statement of grounds of appeal thus constitutes a justified reaction to a new situation that had arisen only at the oral proceedings.

13. The board finds it appropriate to add that the amendments 1.7a and 1.8a to claim 1 of the twelfth auxiliary request are not complex and appear at first sight suitable to address the issues of added subject-matter raised against claim 1 of the respondents' main request.

14. Having regard to the above considerations, the board admitted the twelfth auxiliary request in the appeal proceedings (Article 12(4) and (6) RPBA).

(b) Right to priority

15. The appellant objected that claim 1 of the twelfth auxiliary request did not validly claim priority from the application JP 2016-181176.

16. Compared to the priority application, claim 1 was amended by adding, inter alia, feature 1.3. This requirement limited the female thread in that it should include a varying-thread-width portion having a thread-ridge width gradually increasing and a thread-groove width gradually decreasing toward a centre of the box. The parties agree that this additional feature was taken verbatim from the description of the priority application. In this respect, paragraph [0049] of document D10 was mentioned by the parties. Document D10 was filed by the appellant in the proceedings before the opposition division and marks the changes between the English translation of the PCT-application and that of the priority application. The board notes that paragraph [0049] of document D10 appears to have number [0048] in the original priority application ("(see PDF) 2 1 2 [...]").

17. The appellant's objection was directed against the fact that the additional constraint of paragraph [0049] of document D10 that the thread-groove width of the female thread corresponds to the thread-ridge width of the male thread in the respective varying-thread-width portions was not incorporated in claim 1 of the twelfth auxiliary request. It was initially presented as the first objection under 'Priority Issue B' against claim 1 of the main request on appeal in reaction to the opposition division's conclusion in point 20.3.1 of the reasons for the decision under appeal.

18. The respondents' case was that this allegedly omitted constraint was already included in claim 1 by virtue of feature 1.1, namely the requirement that the female thread is corresponding to the male thread. The respondents also submitted that paragraph [0048] of document D10 required in very similar terms that the ridge width and groove width of the female thread correspond to the groove width and ridge width, respectively, of the male thread in the constant-thread-width portions 111, 211, despite the fact that it was immediately apparent from paragraph [0041] of document D10 that these widths were not exactly the same.

19. The respondents' position on the ambiguous meaning of the expression correspond to in paragraph [0048] of document D10 is convincing. It indeed follows from paragraph [0041] of document D10 that, when the threaded connection has been made up, the stab flanks 11c, 21c are not in contact with each other. Figure 2A clearly illustrates that a gap is present between the male thread 11 and the female thread 21. The respective widths of the female ridges and grooves in the constant thread-width portions 111, 211 are thus different from those of the male grooves and ridges, respectively, even if paragraph [0048] of document D10 indicates that they correspond to each other. This view on the matter does, however, not extend to the varying-thread-width portions 112, 212 described in paragraph [0049] of document D10. Both the description and the drawings of the embodiment disclosed in the priority application indicate without ambiguity that the load flanks 11d, 21d and the stab flanks 11c, 21c are in contact with each other when the connection has been made up so that no gap is present between the male and female threads in the varying-thread-width portions (Figures 2B, 4B and paragraph [0042] of document D10). It then follows that, in the varying-thread-width portions, the widths of the female ridges and grooves is the same as those of the male grooves and ridges, respectively. The expression correspond to in paragraph [0049] of document D10 is thus not to be understood in a broad sense as encompassing variations that result in gaps between the thread flanks.

20. The board does not concur with the respondents either in their view that the additional constraint of paragraph [0049] of document D10 was subsumed under feature 1.1 of claim 1. In the absence of any mention of the varying-thread-width portions, the thread-groove width or the thread-ridge width in feature 1.1, and further considering the ambiguous meaning of the expression correspond to in the description of the constant-thread-width portions in paragraph [0048] of document D10, it cannot be concluded that feature 1.1 must be construed that the grooves and ridges along the entire length of the female thread correspond in width to the respective ridges and grooves of the male thread.

21. In point 20.3.1 of the reasons for the decision under appeal, the opposition division seems to have inferred the additional constraint of paragraph [0049] from features 1.4 to 1.6 of claim 1 of the then auxiliary request 9. However, the board is unable to derive from the general wording of these features ("the load lead is larger than the stab lead", "the load leads [...] are constant over the entire thread length", "the stab lead increases at the switch") whether or not the widths of the individual female ridges and grooves correspond to those of the male grooves and ridges, respectively, in the varying-thread-width portions.

22. Also the additional features 1.7a and 1.8a of claim 1 of the twelfth auxiliary request do not imply the constraint set by the last sentence of paragraph [0049] of document D10. The requirement that, in the varying-thread-width portions of the male and female thread, load flanks of the male thread are in contact with load flanks of the female thread and stab flanks of the male thread are in contact with stab flanks of the female thread does not entail the exact location of the respective points of contact. Thus, the width of a female thread-groove, for example, may not correspond to the width of the male thread-ridge despite there being contact between the stab and load flanks of the ridge and the stab and load flanks of the groove. This is all the more so since the male and female threads of claim 1 are limited to dove-tailed shapes and, as the respondents indicated in the oral proceedings before the board, the width is normally measured at the middle of the flanks.

23. In view of the above, the board concludes that there is no direct and unambiguous disclosure in the priority application of a threaded connection having feature 1.3 of claim 1 without the additional constraint that the thread-ridge width and the thread-groove width of the female thread correspond to the thread-groove width and the thread-ridge width, respectively, of the male thread in the respective varying-thread-width portions, as disclosed by paragraph [0049] of document D10.

24. In a further line of argument, the respondents submitted that claim 1 enjoyed partial priority for those threaded connections where the widths were the same in the varying-thread-width portions. Decision G 1/15 was mentioned in this context. The board is not persuaded. The Enlarged Board of Appeal ruled in decision G 1/15 that, under the EPC, entitlement to partial priority may not be refused for a claim encompassing alternative subject-matter by virtue of one or more generic expressions or otherwise (generic "OR"-claim) provided that said alternative subject-matter has been disclosed for the first time, directly, or at least implicitly, unambiguously and in an enabling manner in the priority document. However, in the present case, claim 1 does not contain any generic expression that can be understood to encompass alternative subject-matter. In fact, none of the features of claim 1 of the twelfth auxiliary request brings the width of the female thread-grooves in connection with that of the male thread-ridges, or the width of the male thread-grooves with that of the female thread-ridges, in the varying-thread-width portions. Therefore, claim 1 is not a generic "OR" claim in the sense of decision G 1/15.

25. For the above reasons, claim 1 of the twelfth auxiliary request does not validly claim priority (Article 87(1) EPC). The effective date is 15 September 2017.

(c) Novelty over document D5 (Article 54(1) and (3) EPC)

26. Document D5 is a European patent application published on 24 July 2019, i.e. after the effective date valid for claim 1 of the twelfth auxiliary request. It originated as a Euro-PCT application published under the PCT as WO 2018/052141 A1 and has a priority date of 16 September 2016. Given that the requirements of Article 153(5) EPC are fulfilled, document D5 is thus comprised in the state of the art under Article 54(3) EPC in respect of the subject-matter of claim 1.

27. The appellant argued by referring to paragraphs [0036], [0041] to [0043], [0045], [0049], [0051], [0058], [0060] to [0062], and [0065] to [0068] that the embodiment shown in Figures 1, 2, 2A to 2D and 3 of document D5 comprises all features of claim 1 of the twelfth auxiliary request.

28. The respondents did not take position on the novelty objection over document D5.

29. Absent any indication to the contrary, the appellant's objection is convincing. Therefore, the board concludes that the subject-matter of claim 1 of the twelfth auxiliary request lacks novelty over document D5 (Article 54(1) and (3) EPC). The twelfth auxiliary request is thus not allowable.

Thirteenth auxiliary request

(a) Admittance

30. The appellant requested not to admit the thirteenth auxiliary request in the appeal proceedings. Its reasons were the same as for the twelfth auxiliary request. The appellant also referred to point 6.3 of the opposition division's communication sent in annex to the summons for oral proceedings and argued that the objection raised therein should have triggered the respondents to file the thirteenth auxiliary request at an earlier stage.

31. Point 6.3 of the opposition division's communication concerned the question whether claim 1 as granted validly claimed a right to priority. More specifically, the opposition division refuted the argument put forward by the respondents that paragraph [0049] of document D10 defined the thread-ridge width of the female thread without reference to the grooves. The respondents' argument was in response to the appellant's objection that the priority application only disclosed the female thread-ridge width in combination with the female thread-groove width, so that claim 1 as granted, by defining the varying-thread-width portion of the female thread by means of the thread-ridge width but without mentioning the thread-groove width, constituted an unallowable intermediate generalisation.

32. The board cannot see how the amendments of claim 1 of the thirteenth auxiliary request are linked to this issue. The respondents added the thread-groove width to feature 1.3 of claim 1 in each of auxiliary requests 9 to 11 underlying the decision under appeal. Rather, the thirteenth auxiliary request must be considered as a reaction to an objection by the appellant raised for the first time at the oral proceedings held before the opposition division, namely that the last two lines of paragraph [0049] of document D10 had been omitted from claim 1 (see point 20.2.1 of the reasons for the decision under appeal).

33. Further considering that the amendments to claim 1 of the thirteenth auxiliary request would, prima facie, overcome the above-mentioned objection of the appellant, the board decided to admit the thirteenth auxiliary request in the appeal proceedings (Article 12(4) and (6) RPBA).

(b) Late-filed objection of added subject-matter

34. At the oral proceedings held before the board, the appellant raised an objection of added subject-matter under Article 123(2) EPC against claim 1 of the thirteenth auxiliary request. Essentially, it was argued that the claim wording did not require any contact between the thread crests and thread roots of the male and female threads in the constant-thread-width and varying-thread-width portions. This was contrary to the disclosure of paragraphs [0041] and [0042] of the application as filed. In the appellant's view, this objection was already raised in its letter dated dated 10 June 2024.

35. The board takes notice that points 10 and 11 of the appellant's letter dated 10 June 2024 already included objections of added subject-matter referring to paragraphs [0041] and [0042] of the application as filed. Yet these were directed against claim 1 of the sixth and seventh auxiliary request, respectively. The last sentence in point 12.5 of the letter may be understood to mean that all the objections presented in the letter also apply to the thirteenth auxiliary request if it were admitted. It is, however, not sufficient to address in a substantiated manner the specific objection against claim 1 of the thirteenth auxiliary request, as was done at the oral proceedings. In addition, the corresponding passages in points 10.3 and 11.3 of the letter are very general and contain ambiguous statements in terms of the features that were supposed to be missing from claim 1 ("These two paragraphs define a combination of contacts and gaps in axial and radial directions between multiple claimed features, and no basis has been given for the selection", "contacts are mentioned but no gaps (or absence of gaps) have been mentioned in the claim", "[l]oad flanks and stab flanks (which are recited in the claim) are mentioned in these passages, but no associated contact (or lack of contacts) have been mentioned in the claim").

36. It follows from the above that the objection under Article 123(2) EPC against claim 1 of the thirteenth auxiliary request is an amendment to the appellant's appeal case made only at the oral proceedings before the board and, hence, after notification of the communication under Article 15(1) RPBA. Pursuant to Article 13(2) RPBA such an amendment shall, in principle, not be taken into account unless there are exceptional circumstances, which have been justified with cogent reasons by the party concerned.

37. No such exceptional circumstances were invoked by the appellant. They are not apparent to the board either. To the extent that the objection was directed against the amendment of the chamfered surfaces of feature 1.8, it could and should have been raised already at the beginning of the appeal proceedings in the context of the respondents' main request or, arguably, even during the proceedings before the opposition division in the context of one of the then auxiliary requests which also claimed the chamfered surfaces.

38. The board did not admit this late-filed objection under Article 123(2) EPC (Article 13(2) RPBA).

(c) Right to priority

39. The appellant argued that claim 1 of the thirteenth auxiliary request does not validly claim right to priority. Three lines of arguments were put forward.

40. The first line of argument was initially presented as 'Priority Issue A' against claim 1 of the respondents' main request on appeal in reaction to the opposition division's conclusion in point 15.7 of the reasons for the decision under appeal. Essentially, the appellant objected that the expression toward a center of the box in feature 1.3 of claim 1 has a different meaning when compared to its use in the particular context of a coupling-type threaded connection in paragraph [0049] of document D10. Without an intermediary coupling element, so argued the appellant, the centre of the box could be translated to the centre of the female thread of the second pipe. Consequently, the addition of feature 1.3 to claim 1 of the priority application resulted in embodiments directed to an integral-type threaded connection in which the width of the female thread-ridge would increase and the width of the female thread-groove would decrease in a direction that was not necessarily away from the end of the box but possibly towards the end of the box, i.e. in the exact opposite direction. Such embodiments lacked basis in the priority application.

41. The board concurs with the appellant that the centre of the box could have a different meaning in the context of an integral-type connection compared to a coupling-type connection. If the box is understood as being restricted to the female threaded region of one of the connecting pipes, as paragraph [0005] of document D10 implies, it would be legitimate to question where its centre should lie. Nevertheless, it must be considered that feature 1.3 of claim 1 also defines the starting point of the varying-thread-width portion of the female thread: the width of the ridge gradually increases and the width of the groove gradually decreases going from the constant-thread-width portion. Given that the corresponding changes of the width of the male thread defined in feature 1.2 of claim 1 occur going from the constant-thread-width portion of the male thread in a direction toward a tip of the pin, it stands to reason that, in a threaded connection of the integral-type, the changes of the female thread width of feature 1.3 also occur in a direction toward a tip of the pin, i.e. a direction away from the end of the box.

42. The appellant submitted that claim 1 did not imply a correspondence between the male and female threads from which one direction of the female thread variations could be excluded. The board disagrees. In a threaded connection with constant load leads of the pin and the box over the entire thread length (feature 1.6), the gradual increase of the thread-ridge width of the female thread must occur in the same direction as the gradual increase of the thread-groove width of the male thread. As the respondents convincingly argued, the appellant's line of argument considered the position of a centre of the box rather than the direction expressed by the claimed expression toward a center of the box.

43. In view of the above, the board concludes that, compared to the priority application, the meaning of the expression toward a center of the box did not change by adding it to a claim which did not specify the type of threaded connection. Also for embodiments of the integral-type connection there is basis in the priority application for the claimed changes of the female thread width towards the centre of the box. The board thus disagrees with the appellant that the right to priority is invalid in view of 'Priority Issue A'.

44. The appellant's second line of argument built further on the objection raised in the context of the twelfth auxiliary request (see point 17. above). While claim 1 of the thirteenth auxiliary request contained a further limitation in accordance with the last sentence of paragraph [0049] of document D10, the requirement of the last-but-one sentence of that paragraph was, in the appellant's view, not reflected by the claim wording.

45. In the board's view, a threaded connection with the following features

- a female thread corresponding to the male thread (feature 1.1),

- with a thread-groove width of the varying-thread-width portion of the male thread gradually increasing going from the constant-thread-width portion of the male thread toward a tip of the pin (feature 1.2),

- with a thread-ridge width of the varying-thread-width portion of the female thread gradually increasing going from the constant thread-width portion of the female thread toward a center of the box (feature 1.3)

- with a thread-groove width of the varying-thread-width portion of the female thread which gradually decreases, going from the constant-thread-width portion toward the center of the box to correspond to the thread-ridge width of the varying-thread-width portion of the male thread (feature 1.3a),

- with constant load leads of the pin and box over the entire thread length (feature 1.6), and

- with contacting load flanks, contacting stab flanks and contacting chamfered surfaces in the varying-thread-width portions of the male and female threads (features 1.7a, 1.8a)

must also comply with the requirement that the thread-ridge width of the varying-thread-width portion of the female thread gradually increases to correspond to the thread-groove width of the varying-thread-width portion of the male thread. In other words, it is not apparent how the load lead could remain constant when the width of the female thread-groove corresponded to the width of the male thread-ridge but the width of the female thread-ridge did not correspond to the width of the male thread-groove. When asked at the oral proceedings, the appellant was not able to produce any counterexample.

46. Hence, it must be concluded that the various restrictions in claim 1 of the thirteenth auxiliary request are such that also the feature disclosed in the last-but-one sentence of paragraph [0049] of document D10 was implicit. The board thus disagrees with the appellant that the right to priority is invalid in view of its second line of argument.

47. The appellant's third line of argument was initially presented as a second objection under 'Priority Issue B' against claim 1 of the main request on appeal in reaction to the opposition division's conclusion in point 20.3.2 of the reasons for the decision under appeal. It was directed against the omission from claim 1 of the physical location of the constant-thread-width portions and the varying-thread-width portions, despite it being disclosed in paragraphs [0054] and [0055] of document D10 on which the amendments of features 1.5 and 1.6 were based.

48. The respondents' view was that the requirements of feature 1.2 of claim 1 necessarily imply that the varying-thread width portion of the male thread was on the tip-portion side of the pin compared to the constant-thread-width portion of the male thread. This argument is convincing. If the width of the thread-groove of the varying-thread-width portion of the male thread gradually increases going from the constant-thread-width portion of the male thread toward a tip of the pin (feature 1.2), this can only mean that the constant-thread-width portion of the male thread lies on the base-end or proximal side of the pin and the varying-thread-width portion of the male thread on the tip-end or distal side. Similarly, it follows from the fact that the thread-ridge width of the varying-thread-width portion of the female thread gradually increases going from the constant-thread-width portion of the female thread toward a center of the box (feature 1.3), that the constant-thread-width portion of the female thread lies on the tip-end side of the box and the varying-thread-width portion of the female thread lies on the base-end side of the box which, in the case of a coupling-type connection, is the central portion of the box. The board further notes that the terms used in paragraphs [0054] and [0055] ("tip portion", "base portion") do not imply a precise location on the pin. Rather, they express arrangement of the different thread portions relative to one another. Consequently, the addition of features 1.5 and 1.6 to claim 1 did not omit any information from paragraphs [0054] and [0055] of document D10 that was inextricably linked thereto. Also the third line of argument is not persuasive.

49. In sum, the appellant did not convincingly argue that claim 1 of the thirteenth auxiliary request does not validly claim priority from the earlier application JP 2016-181176 under Article 87(1) EPC. The effective date of the claim is thus 16 September 2016.

(d) Novelty over document D5

50. As a consequence of the foregoing, document D5 is not comprised in the state of the art under Article 54(2) or (3) EPC in respect of the subject-matter of claim 1 of the thirteenth auxiliary request.

51. The appellant did not present any further objections under Article 54(1) or 56 EPC against the thirteenth auxiliary request. The board thus concludes that the thirteenth auxiliary request is allowable.