Source: Noto CJK

U+331D Square Koruna

U+331D was added in Unicode version 1.1 in 1993. It belongs to the block U+3300 to U+33FF CJK Compatibility in the U+0000 to U+FFFF Basic Multilingual Plane.

This character is a Other Symbol and is mainly used in the Katakana script.

The glyph is a square composition of the glyphs Katakana Letter Ko, Katakana Letter Ru, Katakana Letter Na. Its East Asian Width is wide. In bidirectional text it is written from left to right. When changing direction it is not mirrored. This katakana joins with other adjacent katakana to form a word. U+331D offers a line break opportunity at its position, except in some numeric contexts.

The Wikipedia has the following information about this codepoint:

The koruna, or crown (sign: Kč; code: CZK, Czech: koruna česká), has been the currency of the Czech Republic since 1993. The koruna is one of the European Union's eight currencies, and the Czech Republic is legally bound to adopt the euro in the future.
The official name in Czech is koruna česká (plural koruny české, though the zero-suffixed genitive plural form korun českých is used on banknotes and coins of value 5 Kč or higher). The ISO 4217 code is CZK and the local acronym is Kč, which is placed after the numeric value (e.g., "50 Kč") or sometimes before it (as is seen on the 10-koruna coin). One crown is made up of 100 hellers (abbreviated as "h", official name in Czech: singular: haléř, nominative plural: haléře, genitive plural: haléřů – used with numbers higher or equal to 5 – e.g. 3 haléře, 8 haléřů), but hellers have now been withdrawn from circulation, and the smallest unit of physical currency is 1 Kč.

Representations

System	Representation
Nº	13085
UTF-8	E3 8C 9D
UTF-16	33 1D
UTF-32	00 00 33 1D
URL-Quoted	%E3%8C%9D
HTML hex reference	㌝
Wrong windows-1252 Mojibake	ãŒ
Encoding: GB18030 (hex bytes)	81 39 D9 33

Elsewhere

Complete Record

Property	Value
Age (age)	1.1 (1993)
Unicode Name (na)	SQUARE KORUNA
Unicode 1 Name (na1)	SQUARED KORUNA
Block (blk)	CJK Compatibility
General Category (gc)	Other Symbol
Script (sc)	Katakana
Bidirectional Category (bc)	Left To Right
Combining Class (ccc)	Not Reordered
Decomposition Type (dt)	square
Decomposition Mapping (dm)	Katakana Letter Ko Katakana Letter Ru Katakana Letter Na
Lowercase (Lower)	✘
Simple Lowercase Mapping (slc)	Square Koruna
Lowercase Mapping (lc)	Square Koruna
Uppercase (Upper)	✘
Simple Uppercase Mapping (suc)	Square Koruna
Uppercase Mapping (uc)	Square Koruna
Simple Titlecase Mapping (stc)	Square Koruna
Titlecase Mapping (tc)	Square Koruna
Case Folding (cf)	Square Koruna
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)	Square Koruna
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)	✘
Modifier Combining Mark (MCM)	✘
Math (Math)	✘
Noncharacter Code Point (NChar)	✘
NFC Quick Check (NFC_QC)	Yes
NFD Quick Check (NFD_QC)	Yes
NFKC Casefold (NFKC_CF)	Katakana Letter Ko Katakana Letter Ru Katakana Letter Na
NFKC Quick Check (NFKC_QC)	No
NFKC_SCF (NFKC_SCF)	Katakana Letter Ko Katakana Letter Ru Katakana Letter Na
NFKD Quick Check (NFKD_QC)	No
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
Soft Dotted (SD)	✘
Sentence Terminal (STerm)	✘
Terminal Punctuation (Term)	✘
Unified Ideograph (UIdeo)	✘
Variation Selector (VS)	✘
Word Break (WB)	Katakana
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)	Square Koruna
Bidi Paired Bracket Type (bpt)	None
East Asian Width (ea)	wide
Hangul Syllable Type (hst)	Not Applicable
ISO 10646 Comment (isc)	—
Joining Group (jg)	No_Joining_Group
Joining Type (jt)	Non Joining
Line Break (lb)	Ideographic
Numeric Type (nt)	none
Numeric Value (nv)	not a number
Simple Case Folding (scf)	Square Koruna
Script Extension (scx)
Vertical Orientation (vo)	Tu