Source: Noto Sans Cuneiform

U+12310 Cuneiform Sign U Over U U Reversed Over U Reversed

U+12310 was added in Unicode version 5.0 in 2006. It belongs to the block U+12000 to U+123FF Cuneiform in the U+10000 to U+1FFFF Supplementary Multilingual Plane.

This character is a Other Letter and is mainly used in the Cuneiform script.

The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+12310 forms with similar adjacent characters prevents a line break inside it.

The Wikipedia has the following information about this codepoint:

The Winkelhaken (German: [ˈvɪŋkəlˌhaːkən], "angular hook"), also simply called a hook, is one of five basic wedge elements appearing in the composition of signs in Akkadian cuneiform. It was realized by pressing the point of the stylus into the clay.
A single Winkelhaken corresponds to the sign U (Borger 1981 nr. 411, Borger 2003 nr. 661), encoded in Unicode at code point U+1230B 𒌋.
other signs consisting of Winkelhaken:

A Glossenkeil (Borger nr. 378) is a cuneiform character, consisting of either two Winkelhaken (U+12471 𒑱), or of two parallel short diagonal wedges (U+12472 𒑲, similar to GAM), Borger 2003 nr. 592, which serves as a sort of punctuation, as it were as quote sign, marking foreign words or names, or as separation mark, transliterated as a colon ':'.

two Winkelhaken, MAN, XX "20", Borger 2003 nr. 708

three Winkelhaken, EŠ, XXX "30", Borger 2003 nr. 711, U+1230D 𒌍

four Winkelhaken, NIMIN, XL "40", Borger 2003 nr. 712, U+1240F 𒐏

four Winkelhaken, two of them reversed MAŠGI, BARGI, Borger 2003 nr. 713, U+12310 𒌐

five Winkelhaken, NINNU, L "50", Borger 2003 nr. 714, U+12410 𒐐

six Winkelhaken, LX "60", Borger 2003 nr. 715, U+12411 𒐑

seven Winkelhaken, Borger 2003 nr. 716, U+12412 𒐒

eight Winkelhaken, Borger 2003 nr. 717, U+12413 𒐓

nine Winkelhaken, Borger 2003 nr. 718, U+12414 𒐔

Representations

System	Representation
Nº	74512
UTF-8	F0 92 8C 90
UTF-16	D8 08 DF 10
UTF-32	00 01 23 10
URL-Quoted	%F0%92%8C%90
HTML hex reference	𒌐
Wrong windows-1252 Mojibake	ð’Œ

Elsewhere

Complete Record

Property	Value
Age (age)	5.0 (2006)
Unicode Name (na)	CUNEIFORM SIGN U OVER U U REVERSED OVER U REVERSED
Unicode 1 Name (na1)	—
Block (blk)	Cuneiform
General Category (gc)	Other Letter
Script (sc)	Cuneiform
Bidirectional Category (bc)	Left To Right
Combining Class (ccc)	Not Reordered
Decomposition Type (dt)	none
Decomposition Mapping (dm)	Cuneiform Sign U Over U U Reversed Over U Reversed
Lowercase (Lower)	✘
Simple Lowercase Mapping (slc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Lowercase Mapping (lc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Uppercase (Upper)	✘
Simple Uppercase Mapping (suc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Uppercase Mapping (uc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Simple Titlecase Mapping (stc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Titlecase Mapping (tc)	Cuneiform Sign U Over U U Reversed Over U Reversed
Case Folding (cf)	Cuneiform Sign U Over U U Reversed Over U Reversed
ASCII Hex Digit (AHex)	✘
Alphabetic (Alpha)	✔
Bidi Control (Bidi_C)	✘
Bidi Mirrored (Bidi_M)	✘
Composition Exclusion (CE)	✘
Case Ignorable (CI)	✘
Changes When Casefolded (CWCF)	✘
Changes When Casemapped (CWCM)	✘
Changes When NFKC Casefolded (CWKCF)	✘
Changes When Lowercased (CWL)	✘
Changes When Titlecased (CWT)	✘
Changes When Uppercased (CWU)	✘
Cased (Cased)	✘
Full Composition Exclusion (Comp_Ex)	✘
Default Ignorable Code Point (DI)	✘
Dash (Dash)	✘
Deprecated (Dep)	✘
Diacritic (Dia)	✘
Emoji Modifier Base (EBase)	✘
Emoji Component (EComp)	✘
Emoji Modifier (EMod)	✘
Emoji Presentation (EPres)	✘
Emoji (Emoji)	✘
Extender (Ext)	✘
Extended Pictographic (ExtPict)	✘
FC NFKC Closure (FC_NFKC)	Cuneiform Sign U Over U U Reversed Over U Reversed
Grapheme Cluster Break (GCB)	Any
Grapheme Base (Gr_Base)	✔
Grapheme Extend (Gr_Ext)	✘
Grapheme Link (Gr_Link)	✘
Hex Digit (Hex)	✘
Hyphen (Hyphen)	✘
ID Continue (IDC)	✔
ID Start (IDS)	✔
IDS Binary Operator (IDSB)	✘
IDS Trinary Operator and (IDST)	✘
IDSU (IDSU)	0
ID_Compat_Math_Continue (ID_Compat_Math_Continue)	0
ID_Compat_Math_Start (ID_Compat_Math_Start)	0
Ideographic (Ideo)	✘
InCB (InCB)	None
Indic Mantra Category (InMC)	—
Indic Positional Category (InPC)	NA
Indic Syllabic Category (InSC)	Other
Jamo Short Name (JSN)	—
Join Control (Join_C)	✘
Logical Order Exception (LOE)	✘
Math (Math)	✘
Noncharacter Code Point (NChar)	✘
NFC Quick Check (NFC_QC)	Yes
NFD Quick Check (NFD_QC)	Yes
NFKC Casefold (NFKC_CF)	Cuneiform Sign U Over U U Reversed Over U Reversed
NFKC Quick Check (NFKC_QC)	Yes
NFKC_SCF (NFKC_SCF)	Cuneiform Sign U Over U U Reversed Over U Reversed
NFKD Quick Check (NFKD_QC)	Yes
Other Alphabetic (OAlpha)	✘
Other Default Ignorable Code Point (ODI)	✘
Other Grapheme Extend (OGr_Ext)	✘
Other ID Continue (OIDC)	✘
Other ID Start (OIDS)	✘
Other Lowercase (OLower)	✘
Other Math (OMath)	✘
Other Uppercase (OUpper)	✘
Prepended Concatenation Mark (PCM)	✘
Pattern Syntax (Pat_Syn)	✘
Pattern White Space (Pat_WS)	✘
Quotation Mark (QMark)	✘
Regional Indicator (RI)	✘
Radical (Radical)	✘
Sentence Break (SB)	Other Letter
Soft Dotted (SD)	✘
Sentence Terminal (STerm)	✘
Terminal Punctuation (Term)	✘
Unified Ideograph (UIdeo)	✘
Variation Selector (VS)	✘
Word Break (WB)	Alphabetic Letter
White Space (WSpace)	✘
XID Continue (XIDC)	✔
XID Start (XIDS)	✔
Expands On NFC (XO_NFC)	✘
Expands On NFD (XO_NFD)	✘
Expands On NFKC (XO_NFKC)	✘
Expands On NFKD (XO_NFKD)	✘
Bidi Paired Bracket (bpb)	Cuneiform Sign U Over U U Reversed Over U Reversed
Bidi Paired Bracket Type (bpt)	None
East Asian Width (ea)	neutral
Hangul Syllable Type (hst)	Not Applicable
ISO 10646 Comment (isc)	—
Joining Group (jg)	No_Joining_Group
Joining Type (jt)	Non Joining
Line Break (lb)	Alphabetic
Numeric Type (nt)	none
Numeric Value (nv)	not a number
Simple Case Folding (scf)	Cuneiform Sign U Over U U Reversed Over U Reversed
Script Extension (scx)
Vertical Orientation (vo)	R