[cooper12]

PLOS uses this logo for open access: https://commons.wikimedia.org/wiki/File:Open_Access_logo_PLo.... (an open lock) Based on that Wikipedia uses a closed lock to indicate paywalled sources: https://commons.wikimedia.org/wiki/File:Closed_Access_logo_a.... So how about these: [Closed lock] [Open lock]? (TIL HN doesn't support emoji) I think reddit also allows image use via CSS.

[protomyth]

I would prefer not reusing closed lock since it represents encryption in most browsers.

[cooper12]

Hmm that's a fair point even if it's in a different context since ideally each symbol would retain its own meaning. I'm not sure what a better icon would be then that would be intuitive unless one was decided upon and widely used.

[protomyth]

Its a recent user training issue, so, if it wasn't so soon I would be all happy, but finding a better icon would probably be better.

A book with a lock might work.