List of Acronyms

Everything about Sudoku that doesn't fit in one of the other sections

List of Acronyms

Postby Wecoc » Tue Jan 21, 2020 11:18 pm

This forum uses a lot of acronyms, so I decided to make this list. I hope it will be useful.
Feedback and suggestions will be appreciated.


NS - Naked Set
LS - Locked Set
HS - Hidden Set
LC - Locked Candidates

Note: Inside each Set there are more specific subgroups; Naked Pair (NP), Naked Triplet (NT), etc.
Those are the most basic techniques, you can read about them here.

ANS - Almost Naked Set
ALS - Almost Locked Set
AHS - Almost Hidden Set
ALC - Almost Locked Candidates

Note: ALS is a group of N cells which share N+1 candidates. If they share N+2 you could define it as Almost ALS or AALS, and you can have AAALS and so on. Same happens with AANS, AAHS... More info here.

CoALS - Combined Overlapping Almost Locked Sets Rule
DB - Death Blossom

QNS - Quantum Naked Set
PNS - Pseudo-Naked Set

MSLS - Multi Sector Locked Set
MSNS - Multi Sector Naked Set
MSHS - Multi Sector Hidden Set

SS - Skyscraper

DIC - Double Implication Chain
AIC - Alternating Interference Chain

DP - Deadly Pattern
DR - Deadly Rectangle

Note: You could also have ADP and ADR for Almost Deadly Pattern/Rectangle, the real deadly thing here is the terminology

RP - Remote Pair
ARP - Almost Remote Pair
RT - Remote Triplet

BARN - Bent Almost Restricted Naked Set

EM - Equivalence Marks
GEM - Graded Equivalence Marks

3DM - 3D Medusa
SDC - Sue-De-Coq

UR - Unique Rectangle
AUR - Almost Unique Rectangle
HUR - Hidden Unique Rectangle
EUR - Extended Unique Rectangle

Note: Unavoidable Rectangle and Almost Unavoidable Rectangle are NOT the same as Unique Rectangle and Almost Unique Rectangle, so it's better to not use the acronyms UR and AUR for them.

UL - Unique Loop

IQ - Incompatible Quads

BUG - Bivalue Universal Grave
MUG - Multivalued Universal Graves

HBUG - Hidden BUG

UCC - Uniqueness Clue Cover, yuck!

FC - Forcing Chain
DFC - Digit Forcing Chain
NFC - Nishio Forcing Chain
(D)CFC - (Dual) Cell Forcing Chain
UFC - Unit Forcing Chain

Note: There's also Triple Cell Forcing Chain, Quad Cell Forcing Chain, Region Forcing Chain and Contradiction Forcing Chain, but the acronym is not used.

APE - Aligned Pair Exclusion
ATE - Aligned Triplet Exclusion

CSP - Constraint Satisfaction Problem
DLX - Dancing Links, used to solve CSPs

JExocet - Junior Exocet

Note: You can read basic info about Exocets here. There's also a Senior Exocet but it's not abbreviated as SExocet, probably for the good of all.
Note: On Exocets some also talk about BC (Base Cells), TC (Target Cells) and CC (Cross Cells), but it's not common terminology.

DExocet - Double Exocet
GExocet - Generic (or Generalized) Exocet

Note: You can abbreviate even more using JE (JExocet), SE (Senior Exocet), DE (Double Exocet) and GE (Generic Exocet) but it's not preferred.
Note: Generic Exocets can also be Double and Junior so you can have DGE or JGE...

AGE - Almost Generic Exocet
GE2A - Generalized Exocet with Aligned Targets

SDP - Single Digit Patterns

POM - Pattern Overlay Method
BB - Bowman's Bingo
T&E - Trial and Error

TM - Triangular Matrix
FUD - First Upper Diagonal of a Triangular Matrix
BTM - Block Triangular Matrix
MBM - Mixed Block Matrix
PM - Pigeonhole Matrix
FM - Forbidding Matrix
SPM - Symmetric Pigeonhole Matrix

TDP - Technique of Tracks (Technique des Pistes, in French. More info in this PDF)

SIS - Strong Interference Set
WIS - Weak Interference Set

DLoop - Domino Loop
VLoop - Virus Loop
SK Loop - Steve Kurzhal's hidden-pair loop
SLG - Set Link Graphs

b/b plot - Bilocation/bivalue plot

(W)XYZ-Wing - Basic types of Wings

Note: More info in The Ultimate FISH Guide
More advanced types of Wings are defined here, here and here.

W-Wing - Basic type of Wing, named after George Woods, who discovered it.
M-Wing - Medusa Wing (simplest case of Medusa coloring)
L-Wing - Local Wing
H-Wing - Hybrid Wing
S-Wing - Split Wing
T-Wing - Transport Wing

Note: Check this post for a more extended & updated classification of Wings: March 13 2019
Note: Wings can also be classified based on the placement of V (value) and L (local) links: April 28 2019
More info here: What is XYZ-Wing Hybrid strategy?

BLR - Box Line Reduction

DS - Disjoint Subset
DDS - Disjointed Distributed Subset
ADDS - Almost Disjointed Distributed Subset

ER - Empty Rectangle

Note: ER are formed by lines (ERL) that cross in an intersection (ERI)
The ER can be spotted when an Empty mini-Area (EmA) is observed. More info in the hidden text of this post.
Note: You can read about TowER Cranes and LoadER Cranes here, of course it wouldn't be a good acronym list without some acronym-based puns...

RC - Restricted Common
RCD - Restricted Common Digit
RCC - Restricted Common Candidate [Outdated]

NL - Nice Loop
CNL - Continuous Nice Loop
DNL - Discontinuos Nice Loop

SSTS - Simple Sudoku Technique Set
AST - Advanced Solving Technique

- A pearl is a puzzle where initially the player cannot fill in any cell using SSTS (eliminations could be made, but no cells could be filled in directly)
- A diamond is a puzzle that doesn't have any "backdoor cells" (A backdoor cell is a cell where if you put in the correct value, with or without any logical reason, it would lead to the whole puzzle being solved by further moves under SSTS)


Note: The Eureka notation often abbreviates even more the names of many basic techniques, but I won't include them here.

stte - Singles to the end, sometimes called Singles to end (ste)
btte - Basics to the end
lste - Locked Sets (and singles) to end
lclste - Locked Candidates, Locked Sets (and singles) to end
sstste - Simple Sudoku Technique Set (SSTS) to end


LS - Latin Square

X - Diagonal Sudoku
NC - Non-Consecutive
AK - Anti-King, also known as Ferz
FNC - Ferz Non-Consecutive

AN - Anti-kNight
DP - Diagonal Pairs
FP - Forbidden Pairs
DG - Disjoint Groups (SudokuP)
AC - (Non-Consecutive) Adjacent Cells
CP - Contiguous Psets
SF - Frame Sudoku
GT - Greater Than Sudoku

KCC - Killer Cage Convention
MM - Multiple Modes


P&P - Pencil and paper
PM - Pencil-mark

RPC - Arcilla's Rows-per-Column list
CPR - Arcilla's Columns-per-Row list
EE - Arcilla's Eventual-Elimination
CEC - Candidate-Elimination Cell
DCB - Difference Cover-Base

DDS - Double Diagonal Symmetry of the clues

CP - Conjugate Pair

SE - Sudoku Explainer

SE - Main difficulty score given by the program Sudoku Explainer
ER - Explainer Rating
EP - (Explainer) Pearl rating
ED - (Explainer) Diamond rating

Note: You can read more about rating types in the first post of the Patterns Game

FOL - First Order Logic
MS-FOL - Multi-Sorted First Order Logic
LAS - Local Area Set
MSG - Minimum Set Group

UFG - The Ultimate Fish Guide thread

OTP - One Trick Pony, puzzle that requires only one hard trick

PE - Potential Elimination

SIN - Single Implication Network

NRC-, NRCT-, NRCZ-, and NRCZT- chains - Oriented 3D Chains
N-Rope, N-Braid, Z-Braid, and Z-Rope - Patterns used in Braid Analysis

MDCD - Multiple-digit Concept Diagrams

WU - Weekly Unsolvable Sudoku from Andrew Stuart's webpage

WSC - World Sudoku Championship
WPC - World Puzzle Championship

WTR - Wecoc Totally Rules (Ok, I just made that one up)
Last edited by Wecoc on Fri Jan 24, 2020 1:22 pm, edited 2 times in total.
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Re: List of Acronyms

Postby Mauriès Robert » Wed Jan 22, 2020 9:02 am

Hi Wewoc,
It's a very good idea to have made this list, because for those who, like me, have been on the forum for a short time, it will help a lot to understand the comments.
A comment on the TDP.
You've made a link to a topic in the forum. There is an explanatory text in English more convenient with the following link : that it would be better to propose.
Mauriès Robert
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Location: France

Re: List of Acronyms

Postby Wecoc » Thu Jan 23, 2020 5:07 pm

Mauriès Robert wrote:You've made a link to a topic in the forum. There is an explanatory text in English more convenient with the following link

Ok, I included both ;)
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Re: List of Acronyms

Postby eleven » Mon Jan 27, 2020 10:22 pm

Seems, that no moderators are around anymore. Should become a sticky thread.
Brave work.
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Re: List of Acronyms

Postby tarek » Tue Jan 28, 2020 1:18 pm

I should have posted earlier,

I agree with eleven that plenty of work has been done here in collating this. Well done!

I would probably post somewhere down this thread the short terms for techniques that I've included with Sukaku explainer command line interface.

As Sukaku explainer is still evolving. I will wait a bit longer before posting them

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Re: List of Acronyms

Postby rjamil » Tue Jan 28, 2020 1:49 pm

Hi all,

1to9only gives acronyms to most of the techniques here.

Hope that remaining techniques will also be covered for common/acceptable suitable acronyms soon.

R. Jamil
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Location: Karachi, Pakistan

Re: List of Acronyms

Postby jco » Sat Feb 06, 2021 5:41 pm

Hello Wecoc,

I have three acronyms to suggest:

LoL meaning "law of leftovers" (used here)

ALP meaning "almost locked pair" (used sometimes in the puzzle section).

In "others":

meaning of OP (see mith's post)

[EDIT: removed incorrect meaning for OP (thanks mith!)
Last edited by jco on Sat Feb 13, 2021 11:13 am, edited 1 time in total.
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Re: List of Acronyms

Postby mith » Sat Feb 13, 2021 12:59 am

OP on forums usually means Original Post or Original Poster.

This hasn't really been used on the forums outside of a puzzle title, but this has caught on elsewhere and I'm sure I will use it at some point:

SET - SET Equivalence Theory

(This is my pet blanket term for the sort of argument used in e.g. Garam Masalas, using intersections of houses to equate two sets of cells (modulo complete sets of 1-9) - which is an alternate way of looking at equivalent MSLS/MultiFish/etc. deductions.)
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