There is only one file type that uses the .TLX extension:
Standard Dictionary File
Dictionary file used by various programs; contains a word list for a particular language, such as American English, British English, or Spanish; sometimes distributed alongside a .CLX file, which contains a more comprehensive word list.
TLX files are used by application spell checkers for validating documents. If they are distributed with a CLX dictionary file, they usually contain a shorter list than the CLX file.
Updated: January 11, 2011