With the following exceptions, TCC treats upper case and lower case letters identically:

 

The relational operator EQC (in IF, IFF, DO, etc.)

The character manipulation functions @ascii, @unicode, @repeat, @replace, @similar, @strip and @wild.

 

The codes used to specify units of storage size (kKmMgGtT) in:

 

size ranges

disk space and file size reporting functions