Hello, Consider the following: \definesynonyms [ACRONYM] [ACRONYMS] [\FULL] [\SHORT] \ACRONYM{DLL}{Dynamic-Link Librar\doifnextcharelse{s}{ie}{y}} Why \FULL{DLL}s does not do what I expect it to do? I assume that it's because `\doifnextcharelse' expands before `\FULL'. So how to achieve the desired effect? Thanks. Kind regards, Alexander