(I'd have put an example link on "history", but Danbooru's "links in comments" system is weird to me.)
Put a full quote mark, what you want the words to say, a full quote mark, a colon, then your URL. If the URL's doing something stupid in the preview, you can put the URL itself in square brackets. Links to anything on Danbooru can be made domain friendly by taking everything off behind the first slash. So to make a link to this post, instead of using [post #2269605] you should just use [/posts/2269605]. The result is this link.
If you don't want custom text you can link some things just by typing their type, a space, a number sign, then their number. These are just typed straight with no markup or wizardry: post #2269605, pixiv #55180119, topic #4782.
Then more advanced stuff. To link to the wiki page for a tag, put it in two sets of square brackets. To make custom text for it, you can put two opening brackets, the one tag, then a vertical bar (Shift+\ on an American keyboard), then the text you want shown, then two closing brackets. Like this. You can also link post searches by using curly brackets, though you must replace spaces in single tags with underscores. Like this: multiple_girls comic. I don't think custom text works for these.
You should be able to click Reply on this comment to see the examples expanded. Of course this is all in the link below the comment box, but in much fewer words.
I think it's unfair that her Puchi got away clean. She was in on things as much as Sazanami.
Sazanami is the new Nenohi. It's not about "deserving it", the puchis are "cuter", so they never get punished, (Teetoku being a pseudo-exception in that she and her sister are not entirely puchis,) while the "humans" suffer the pain for comedic effect.
Hmm, these posts that get their links thrown in comments in other posts, tons of comments in their own right, tons of pools and general "meta" conversation always seem to have a low score and fewer favourites than I'd expect..
Sazaaa♪
Puchi 752 Here's the Oni
Sazanami-chaaan♪Okayyy, next is...Uh, well...
start throwing those beans!
Put this on, okay?♪
Aren't there a lot of b-battleship-class puchis around...?All right, everyone...