That's a pretty unintuitive use, since "sigil" is more commonly used (in programming languages) as a single symbol, as in a non-alphanumeric character that's used as some kind of syntax.
Right so the $ in PHP or @ in Perl would be a sigil, (and even the $ and % in QBasic, am I dating myself?) and the # in this example and all C code and some Swift code would be a pragma. Seems pretty cut and dry.