| Footnotes can be very handy in Everything 21. They are fairly easy to create, too!2. There are even different styles of marking footnotes*!
Footnotes are your friend! Learn more about how to use footnotes3, and things to avoid with them**.
1A footnote usually carries tangental, yet extraneous, knowledge to the main text. They are a powerful tool to use. You can put awkward dates in them, you can give credit to sources with them, you can even spice up a stodgy, book larnin' node with some related humor to the line at hand, just to lighten the mood, and placate those noders who would mod down an entirely factual yet slighty (to extremly) boring node4. In general, Footnotes are a good thing.
2 Creating a footnote is easy! Here's how: You put a unique and easily identifiable character immediatly to the right of the last word of the thought you wish to extend in a footnote. If a sentence changes direction in mid-sentence5, or there was a comment to be made about just a sentance fragment6, filfre to footnote it!
The best way to footnote, in my opinion, is the use of superscript. Superscript is very effective in screaming 'I am a footnote reference' when used in non-formulaic circumstances. Doubly so when using sequential numbers as the footnote indicators7.
To create these nigh-magical feats of superscripting, you need only apply some HTML wizardry. The <SUP>tag turns all inside of it into superscript</SUP> That's all there is to it. If you want subscript for some reason8, you only need surround said text with the <SUB>tag, and viola! Instant subscript!</SUB>
If for further ineffable reasons you want to use the asterisk instead, you need only hit shift-8. If this doesn't work9, erase the erroneous character, look around the board for the star, and hit that key in conjunction with the shift key. If that still doesn't work, call your local consultant. ;)
* The plain asterisk can be very effective, and certainly requires no html tags. However, you might find it more stylistic or snazzy to make a footnote asterisk in superscript, like***.
3 Okay, we've covered when to use them, and how to use them in footnote2 above. One last trick I can think of that's unique to our little node-haven would be the ability to have your footnote in it's own node. Now, how this'd work is fairly simple. Through the magic of the E2 [linked-node|displayed-text] operator, you could link a node via a footnote. This'd have to be done wisly, and the only uses I can think of it are when you have a long-named node that's relevent tangentally and you don't want to break the flow of the writeup. Use with caution, it is a prototypical technique that only 4 out of 7 scientists deem safe.
** Mixing asterisks and subscripts like this is a bad thing to do. It can lead to confusion, nausea, and halitosis.
4 This is most definitly a very bad thing. It hurts hard-writing noder's feelings! ;_;
5 Which you should generally avoid, although it can be worked cleverly if used wisly and sporadically.
6 Like this footnote's origin, and the previous one's to boot :)
7 Non-sequential numbers would be wacky, but confusing. Single, sequential letters could work dandily, but go out of sequence and it can get weird again. I'd stay away from using entire superscripted words as the footnote handles. That's just weird having words float in mid-air like that :o
8 Some people may find superscripting the footnote's handle, then subscripting the footnote itself a nice way to distinguish between main text and footnote text stylistically.
As for me, usually I go unformatted in footnote text, but sometimes I change my mind on a whim. :)
YMMV
9Then you have a different keyboard than I :)
*** See? Aren't these asterisks nicer than the big ones? I thought so...
10Ah! There is no footnote '10'! I tricked you! You should never have extra footnotes. They're here to be a visual link. Self-Referenced notes within the same node. Your eyes never should have been drawn to this wayward footnote, as there's no parent-handle to send you.
...
Let us not speak of this again. | 
