[luuuzeta]

The author defines a _sigil_ as follows:

* a non-alphabetic character

* that is at the start of a word

* that communicates meta-information about the word.

He gives the example of `echo $USER`, where `$` is a single that communicates that `USER` is a variable, presumably with some contents. Thus, I'd wager `$` is a sigil in `$foo`.

[__MatrixMan__]

I suppose "word" is the constraining factor there, I was thinking of > and # as sigils too, which--if you're willing to be a bit loose with what a "word" is--contradicts that they're unpopular.