Bidirectional character type (Unicode character property Bidi_Class)[1]
Type[2] Description Strong/​Weak/​Neutral
effect, or Explicit
Directionality General scope Bidi_Control character[3]
L Left-to-Right Strong L-to-R Most alphabetic and syllabic characters, Han ideographs, non-European or non-Arabic digits, LRM character, ... U+200E LEFT-TO-RIGHT MARK (LRM)
R Right-to-Left Strong R-to-L Hebrew alphabet and related punctuation, RLM character U+200F RIGHT-TO-LEFT MARK (RLM)
AL Right-to-Left Arabic Strong R-to-L Arabic, Thaana and Syriac alphabets, and most punctuation specific to those scripts U+061C ؜ ARABIC LETTER MARK (ALM)
EN European Number Weak European digits, Eastern Arabic-Indic digits, ...
ES European Separator Weak plus sign, minus sign, ...
ET European Number Terminator Weak degree sign, currency symbols, ...
AN Arabic Number Weak Arabic-Indic digits, Arabic decimal and thousands separators, ...
CS Common Number Separator Weak colon, comma, full stop, no-break space, ...
NSM Nonspacing Mark Weak Characters in General Categories Mark, nonspacing and Mark, enclosing (Mn, Me)
BN Boundary Neutral Weak Default ignorables, non-characters, control characters other than those explicitly given other types
B Paragraph Separator Neutral paragraph separator, appropriate Newline Functions, higher-level protocol paragraph determination
S Segment Separator Neutral Tab
WS Whitespace Neutral space, figure space, line separator, form feed, General Punctuation block spaces This set is smaller than Unicode whitespace list
ON Other Neutrals Neutral All other characters, including object replacement character
LRE Left-to-Right Embedding Explicit L-to-R LRE character only U+202A LEFT-TO-RIGHT EMBEDDING (LRE)
LRO Left-to-Right Override Explicit L-to-R LRO character only U+202D LEFT-TO-RIGHT OVERRIDE (LRO)
RLE Right-to-Left Embedding Explicit R-to-L RLE character only U+202B RIGHT-TO-LEFT EMBEDDING (RLE)
RLO Right-to-Left Override Explicit R-to-L RLO character only U+202E RIGHT-TO-LEFT OVERRIDE (RLO)
PDF Pop Directional Format Explicit PDF character only U+202C POP DIRECTIONAL FORMATTING (PDF)
LRI Left-to-Right Isolate Explicit L-to-R LRI character only U+2066 LEFT-TO-RIGHT ISOLATE (LRI)
RLI Right-to-Left Isolate Explicit R-to-L RLI character only U+2067 RIGHT-TO-LEFT ISOLATE (RLI)
FSI First Strong Isolate Explicit FSI character only U+2068 FIRST STRONG ISOLATE (FSI)
PDI Pop Directional Isolate Explicit PDI character only U+2069 POP DIRECTIONAL ISOLATE (PDI)
Notes
1. ^ Unicode Bidirectional Algorithm (UAX#9), As of version 6.3.0
2.^ Possible Bidirectional character types for character property: Bidi_Class or 'type'
3.^ Bidi_Control characters: Twelve Bidi_Control formatting characters are defined. They are invisible, and have no effect apart from directionality. Nine of them have a unique, overruling BiDi-type that is used by the algorithm. Their type is also their acronym (e.g. character 'LRE' has BiDi type 'LRE').