Emanuel Berg <moasenwood@zoho.eu> writes:

> Maybe has something to do with asterisk? :)

Sounds reasonable to me.

As a quick experiment, adding the rest of the symbol constituents (of
the visible ASCII complement from `lisp-data-mode-syntax-table') to the
relevant `erc-button-alist' member's regexp appears to open things up.
At least it makes `let*' and `ring-insert+extend' light up, as well as
`-->' and `dash-expand:&hash?'. But who knows? Maybe folks more familiar
with this module will have brighter ideas.

(Also, it looks like this stuff touches every message, so we should
probably be somewhat careful.)