This depends on which version of VFP is used. In newer versions of VFP alltrim() is in deed legal, but not in some older versions.

>ALLTRIM(movehist.destjob) is a perfectly valid index key and will be used by Rushmore to optimize the query.
>
>>ALLTRIM(movehist.destjob) is NOT a valid index key, since it will not give a fixed length.