>>90
If you link to a single post, or several posts separated by commas, e.g. >>90,91, then it displays only those posts. If you link to a range of posts, e.g. >>90-91, then it displays >>1 as well. If you want to link to a range without including >>1, put an "n" in front of the number, e.g. >>n90-91. If you link somewhere out of range, e.g. >>1000, then it just displays the entire thread.

There are a few others, too. You can use >>q90 for all posts linking to >>90, >>l90 for the last ninety posts, and >>r90 for ninety random posts in the thread.