3.1 Replacement or removal of a feature from a claim
The replacement or removal of a feature from a claim does not violate Art. 123(2) if the skilled person would directly and unambiguously recognise that:
the feature was not explained as essential in the disclosure;
the feature is not, as such, indispensable for the function of the invention in the light of the technical problem the invention serves to solve; and
the replacement or removal requires no real modification of other features to compensate for the change.
In case of a replacement by another feature, the replacing feature must of course find support in the original application documents, so as not to contravene Art. 123(2) (see T 331/87).