>Can anyone refer me to an authoritative and thorough resource for the many uses for this command? I work with data conversions/translations and use this command daily, but still don't grasp the finer nuances. Any help would be greatly appreciated!

All SCAN...ENDSCAN really does is a DO WHILE loop with an implicit SKIP on each iteration. FOR allows you to specify a filter condition with an implied scope of ALL that examines all records meeting the criteria of the FOR clause; WHILE allows you to specify a filter with an implied scope of REST that terminates as soon as a record that does not meet the criteria of the WHILE condition is encountered.

If you can't figure it out from the VFP docs, which detail this quite explicitly, buy a copy of Hacker's Guide To Visual Foxpro 6.0, which provides extensive documentation not included in the MS-supplied VFP on-line documentation. I'd suggest a more general text on programming in VFP as a starting point, since the operation of scoping on commands sin't specific to the SCAN...ENDSCAN command; any command that supports FOR and WHILE clauses has the same scoping issues.