If you do not have your message boards enabled, and don't want to enable them, you can use your Calendar's monthly view to navigate to the Read Comments page for the entry you would like to mark as a memory. (If you have not enabled comments on your journal, people will still not be able to comment on your entries, even if they visit this page.)
Is it necessary to mention this?
Like journal entries, memories can be marked with three different security levels.
Well, this isn't true. I'm not sure how it should be phrased, but I read that sentence as saying that journal entries can be marked with three different security levels, rather than four (or two, I suppose, for a community entry). "Like journal entries, memories can be marked with different [or differing?] security levels." That sounds awkward, I know, so alternative phrasings?
To delete a memory, simply erase whatever description you have given the memory, and then hit the "submit" button.
"Whatever" is an odd word to use here. How about just changing it to 'the'? And 'the memory' seems redundant, while 'and' is also a bit unnecessary. "To delete a memory, simply erase the description you have given it, then hit the "submit" button. "
Moving on from that FAQ, I'd like to suggest that the final paragraph of FAQ 138 (Where do I go to learn more about S1 customisation?) be modified to mention looking for customisation help in communities. Sample wording:
"Please note that detailed customization support is outside the realm of LiveJournal Support. If you require further assistance in using HTML or CSS to customize your journal, you can search for "HTML tutorial" in your favourite search engine. Note also that several LiveJournal communities deal with journal customization, and you may be able to receive one-to-one help by posting there. For information on finding a community, please see this FAQ: http://www.livejournal.com/support/faqbrowse.bml?faqid=85"
I'd imagine there are arguments against this, given that some communities provide overrides that cause problems in some browsers, but customisation communities are very useful in general. Also, FAQ #172 (Where can I go to learn more about advanced S2 customisation?) mentions communities as being helpful in finding customisation assistance. It might also be better earlier in the FAQ (as in the S2 FAQ), rather than at the end, so, comments? And rewording would be especially good; I'm not fond of how I've phrased that.