This article is from the Crosswords FAQ, by James A. Lundon (jlundon@xstacy.enet.dec.com) with numerous contributions by others.
Roy Thearle has outdone himself by putting together an every better
description of some of the gimmicks used in crossword setting. Many of
the methods described below could be considered to be only seen in
'specials' but, nonetheless are very interesting to would be setters out
there trying to think up of new ways to confuse the solver :-). All
examples have CROSSWORDS as the answer:
Clues
=====
Unclued No clue is given, and the answer is to be
deduced from context, e.g.
1. (10)
Straightforward definition e.g.
2. Puzzles involving word-grids (10)
Quiz style Definition in the form of a question, e.g.
3. Which word puzzles were first published
in the `London Daily Mail' in 1925? (10)
Riddle Similar to previous, but usually involving
some form of word play, e.g.
4. What puzzles create arguments? (10)
Missing word from quotation 5. "the original acrostic form developed
into --- early in the next century" (10)
Missing word from prose A passage of prose is given in which the
answer has been replaced by the grid number
at which it is to appear, e.g.
"I love doing [6ac]; even those by Kea".
Call my bluff Three definitions of related or similar
words are given; one of the words is the answer
e.g.
7. 3.5ft weapons; odd beaked birds; puzzles (10)
{longswords/crossbills/crosswords}
Semi-homonyms Two definitions are given of words which differ
only in one letter, one of which is the answer,
e.g.
8. Forms meadow plants. (10)
{crosswords/crossworts}
Encrypted The clue is an encrypted form of the answer,
normally with the alphabet replaced by numbers
1-26 in some order, but sometimes by a
substitution code. Occasionally, a clue of one
of the other types is encrypted. e.g.
9. 1-2-3-4-4-5-3-2-6-4 (10)
10. Smelly Emil (10)
11. Abcde dfghbi jklmne. (10)
{encrypted clue 8.}
Straightforward anagram e.g.
12. Dross crows (anag.) (10)
Subsidiary indication only Effectively, a cryptic clue without a definition
e.g.
13. Holy symbol incorporating weapon. (10)
{sword in cross}
Definition and anagram A straightforward definition of the answer
juxtaposed with an anagram of it (in either
order). Sometimes the anagram and definition
are written so as to make it unobvious which
is which, e.g.
14. Forms dross crows. (10)
15. Orcs' swords set puzzles. (10)
Definition & letter mixture A line of text containing both a synonym of the
answer, plus a hidden anagram of it. e.g.
16. When composing puzzles, always listen to
compact discs, or drowsiness sets in. (10)
~~~~~~~~~~~~~
Previous with extra letter As above, but the hidden anagram contains a
superfluous letter, e.g.
17. Warriors (orcs) saw death cause problems.
~~~~~~~~~~~~~~~~ (10)
Cryptic e.g.
18. Holy symbol embracing weapon puzzles. (10)
{sword in cross}
Spoonerism There are two forms of this. Either (i) the clue
contains a spoonerism which must be fixed before
solving (normally in the definition part),
or (ii) the subsidiary indication is
a definition for a spoonerized version of the
answer, e.g.
19. Holy symbol embracing weapon - triptych
kempt Asians. (10)
{i.e. cryptic temptations; sword in cross}
Indirect anagram A cryptic clue in which the subsidiary
indication contains a synonym for an anagram
of the answer, plus anagram indicator, e.g.
20. Forms miscreate ogres with weapons. (10)
{i.e. "orcs" (anag.) + "swords"}
Unnumbered A clue with no number, the position of the
answer being determined by the solver, e.g.
Forms miscreate orcs with weapons. (10)
{as previous}
Cryptic using clue number A cryptic clue in which the clue number is part
of the clue, e.g.
100. Rod rows badly around ship, causing
problems. (10)
{C + SS in "rodrows" (anag.)}
Superfluous letter A cryptic clue in which all occurrences of
one letter must be removed before solving,
e.g.
21. Forms torcs, toff, and tepees. (10)
{deleted letter is T;"orcs"(anag.)+"swords"}
Ambiguous A cryptic clue with two (or more) equally valid
answers, e.g.
22. Angry tellings-off that could cause
confusion. (10)
{cross-words or cross-talks}
Concatenated Two cryptic (or occasionally other) clues run
together, e.g.
23. Holy symbol embracing weapon puzzles
religious pacifist - shudder and run? (10;6)
{crosswords & quaker}
Vowelless Cryptic (or other clue type) with the vowels
removed, e.g.
24. Hl smbl mbrcng wpn pzzls. (10)
Cryptic with pun Cryptic clue where one word must be replaced
with a homophone before solving, e.g.
25. Holy cymbal embracing weapon puzzles. (10)
{cymbal -> symbol}
Misprint One letter in the clue (usually in the
definition) must be replaced by another before
solving, e.g.
26. Holy symbol embracing weapon muzzles. (10)
{muzzles -> puzzles}
Missing letter One letter must be added to the clue
(usually in the definition) before solving, e.g.
27. Holy symbol embracing weapon poses. (10)
{poses -> posers}
Cryptic with superfluous One word in the clue should be ignored. This
word is sometimes also known as "red herrings".
e.g.
28. Sauron forms miscreate orcs with
weapons. (10)
{"sauron" is superfluous;orcs(anag)+swords}
Location indication The clue is preceded or followed by a cryptic
indication of the location for the answer,
e.g.
Went in river - in also - row forms. (10)
{"went" and "in" in "Tyne -> twentynine;
cross-words}
Printer's devilry A passage of prose from which the solution
has been removed, and the word breaks and
punctuation changed, e.g.
30. Form a king, Mum - it hinges; sent
I ally, reigns. (10)
{for making muCROS SWORDSmithing
essentially reigns}
 
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