Which features are required in ST.26 but not in ST.25?

Annex VII to WIPO Standard ST.26 provides guidance on how to convert an ST.25 sequence listing into ST.26 format without adding or deleting subject-matter. It is highly recommended that you follow this guidance. In particular, the teaching in the description accompanying the ST.25 sequence listing must be checked very carefully to avoid added subject-matter. 

Scenario 8 in Annex VII to WIPO Standard ST.26 lists the ST.25 feature keys that are not available in ST.26 and describes how to represent such ST.25 feature data in ST.26 format without adding or deleting any subject-matter. 

In WIPO Standard ST.26, the feature key "source" is mandatory for every sequence, in addition to the qualifiers "organism" and "mol_type" (paragraph 75 of WIPO Standard ST.26).  

The value of the "mol_type" qualifier has to be selected from a list of predetermined terms as defined in Annex I of the standard (section 6, qualifier mol_type 6.39; section 8, qualifier mol_type 8.1).