... which can be used in a journal entry to hide the rest of the entry. When the entry appears in your journal or on someone's Friends page, by default, everything after an <lj-cut> tag will be replaced by a link to the Read Comments page. The Read Comments page always displays the entire entry as well as the comments made on it.
If you want your post to have text cut from the middle, your entry would look like the following:
Your opening text goes here
<lj-cut> Your cut text goes here</lj-cut>
The rest of your entry goes here
By default, the link will say "Read more", but if you want it to say something else like "Cut off here", you can write the tag as
<lj-cut text="Cut off here">
Additions/deletions/changes/comments welcome. :)