These links are maintained by email@example.com.
When I first started maintaining this list of links (on SEFLIN), several years ago, I tried to include every MED site I ran across. That's much more difficult now with so many new sites being added all the time. Also now there are a number of other good lists of links around.
So... what I'm doing now is keeping links I used to have until they break. Other than that, I'll put in links I feel like putting in, possibly as part of a reciprocal agreement or just because I like the target site.