A more general variation of the argument specificator o[\x] could be that if the argument is not present, then the command \x is executed. Then \x should be a command declared with \DeclareDocumentCommand, but the argument specificator should have the corresponding o[\x] removed. So, for example, in \DeclareDocumentCommand \Initial {o[\InitialNoLeading]mo[\InitialNoTrailing]} { \MakeInitial {#1}{#2}{#3} } one should also have the declarations \DeclareDocumentCommand \InitialNoLeading {mo} \DeclareDocumentCommand \InitialNoTrailing {om} where the ``o'' argument specificators can have new optional argument if so needed. Hans Aberg * Email: Hans Aberg <mailto:[log in to unmask]> * Home Page: <http://www.matematik.su.se/~haberg/> * AMS member listing: <http://www.ams.org/cml/>