3.2. Decisions allowing claims directed to overlapping subject-matter
3.2.2 Overlap relates to dependent claim
In T 118/91 the board (deciding on the allowability of amended claims of the parent patent in opposition proceedings) stated that it could find nothing to support the contention that features forming part of the subject-matter of the divisional application could not be the subject of a dependent claim in the parent application. The board agreed with the Guidelines that, as a general rule, one application may claim its own subject-matter in combination with that of the other application. This approach does not lead to "double patenting" in its normal sense. In this particular case, the board was satisfied that any danger of "double patenting" had been eliminated by extensive restriction of the claims in the divisional application.
In T 2907/19 the board concluded that the prohibition of double patenting was not pertinent to the fifth auxiliary request because independent claim 1 thereof was different from independent claim 1 of the granted parent application and thus did not define the same subject-matter. According to the board, this was not precluded by the fact that claim 1 of the fifth auxiliary request corresponded to dependent claim 2 of the granted parent application (see, however, T 1128/19 in II.G.3.3.2).