Hi Charles,
Double-quotes for filenames with space is a good news.
I guess Microsoft sees it that way too.
Note that <co2.exe -32 -aCaption.o2bas> do not contain any space and will continue to be ambigious,
It might a rare case, still is <-a> a switch, or part of the filename?
I will always use double-quotes in my pre-compiler to avoid any misinterpretation.
By curiosity, I wanted to know if I can put the switches after filenames.
With no confirmation, I will play safe to avoid possible future problems.
Thank you very much Charles.