Hacker wants a diary tag to reference older entries. I assume he means for one's own diary. More interesting would be linking to another person's entry. Advogato is a closed system, so automatic thread trees should be straightforward. (I know, go code it..)

However, it seems the cross-post precedent (set by Raph?) is to link <person>, not a-href an entry. Which makes thread-tracking cumbersome if you don't read the site daily. Any reason for doing this, folks? Surely, not laziness! :)