unfathomable comment in psqlscan.l

While reviewing Pavel's patch for variable quoting in psql, I came
upon the following comment in psqlscan.l:

/*
* The variable value is just emitted without any
* further examination. This is consistent with the
* pre-8.0 code behavior, if not with the way that
* variables are handled outside backslash commands.
*/

I cannot figure out for the life of me what this is referring to. It
seems to date back to 2004, when the old psql lexer was rewritten to
use flex. But I can't figure out what "further examination" someone
might have expected, or how it's inconsistent with the how things are
"handled outside backslash commands".

Help?

...Robert