The sign "DO-what?" or "what-DO" is sometimes listed as "#DO" because it is a
lexicalized form of spelling the letters "D" and "O."
To do this sign, turn your hands palm up in "D" handshapes and hold them in
front of you with your index fingers pointing out/forward. Then
keeping your hands in that position, spell the word "DO" twice.
More advanced signers tend to do the same thing except they have
"mutated" the "D" handshapes into "G"
handshapes. The movement for this variation is to bring the pads of the
index fingers and the thumbs together twice.
Make sure to use a "Wh-q"
facial expression with this sign because it translates to "What are/is
we/he/she/it doing?" If you put a y/n-q facial expression on this
sign it means, "What did I do? Why are you on my
DO-what? (one handed version)
(What are you doing!?)
Side view: (G hand version)
WHAT-DO? (D hand variation)
Notice, you can use a "D" handshape instead of the "G"
A student asks: Can the sign "what-do" be used for asking "what do I do?"
i.e., "Suppose, fingerspelling, make mistake, what-do?"
Response: The what-DO sign can indeed be used as you suggest. I
might modify your sentence a bit as follows:
"Suppose, DURING ME fingerspell, mistake-[version], I SHOULD what-do?"
And while there isn't one right or wrong way to ask that question, the
"during" and "should=must/need/have to" signs will clarify that you are
seeking to know how to handle spelling errors.
-- Dr. Bill