I post about science quite a bit, and when I do, I try to link to the “primary” literature – peer-reviewed research articles in professional journals. But even in this modern age, lots of professional journals charge for access. Sometimes a lot. I get through on my university’s institutional subscription – but that doesn’t cover everyone. So I’ve been trying to mark links to journal articles based on whether it’ll cost you to read the full text, but I haven’t been happy with the way it looks. Therefore, I’m instituting a set of simple abbreviations, which I’ll append to linked text to indicate access levels:

• [$$] = total lockdown; nothing but the title is free online
• [$-a] = the article’s abstract is free, but more will cost you
• No mark = totally free access

Check out an example of how this looks in a post. Links to an article at PLoS, which is fully open-source, aren’t marked. But links to an article at Science get the [$-a] mark. Links to article titles in the “References” section at the end aren’t marked one way or the other – I sort of assume those don’t get the same kind of follow-through that the in-text links do.