If an application relates to a rubber composition comprising several ingredients and the applicant seeks to introduce the information that a further ingredient may be added, then this amendment is normally objected to as infringing Art. 123(2).
In the case of a disclosure of both a general and a preferred range, a combination of the preferred disclosed narrower range and one of the part-ranges lying within the disclosed overall range on either side of the narrower range may be derivable from the original disclosure of the application.
In an application which describes and claims an apparatus "mounted on resilient supports", without disclosing any particular kind of resilient support, an objection is raised if the applicant seeks to add the specific information that the supports are, or could be, e.g. helical springs.
If, however, the applicant were able to demonstrate that the drawings, as interpreted by the skilled person, show helical springs, the specific mention of helical springs would be allowable, at least in the context of the specific embodiment where it is disclosed (see also H‑V, 3.2.1).