Igor asked...

>What are these selectors (:Test:Yes: :Test:No: :Test:Yes:No: :Test:No:Yes:)?

These were synonyms for ifTrue/ifFalse in SQ2K

>And why they need special handling..

For the same reason as ifTrue/ifFalse.

>And what SQ2K means?

SQ2K, (named as the year 2000 was approaching) was an "alternate syntax" experiment that you may find in the archives.  At one point it was well enough supported that you could view code in the new syntax, type and compile new code in it, but fileOuts and the changes file continued to work in the old ST80 format.  The project was dropped shortly after everything worked ;-).

	- Dan