|
Applicable Unicode
Versions |
Constraints |
|
Unicode
1.1.5+ |
The
General_Category property value
Control (Cc) is immutable: the set of code points with that
value will never change. |
|
Unicode
1.1.5+ |
The
Canonical_Combining_Class property
values are limited to the values 0 to 255. |
|
Unicode
1.1.5+ |
All characters
other than those with General_Category
property values Spacing_Mark (Mc)
and Nonspacing_Mark (Mn)
have the Canonical_Combining_Class
property value 0. |
|
Unicode
2.0.0+ |
The
General_Category property value
Private_Use (Co) is immutable: the
set of code points with that value will never change. |
|
Unicode
2.0.0+ |
The
General_Category property value
Surrogate (Cs) is immutable: the set of code points with that
value will never change. |
|
Unicode
2.0.0+ |
Once a
character is assigned, both its Name and its
Jamo_Short_Name will never change. |
|
Unicode
2.0.0+ |
Canonical
and compatibility mappings (Decomposition_Mapping
property values) are always in canonical order, and the resulting
recursive decomposition will also be in canonical order. |
|
Unicode
2.0.0+ |
Canonical
mappings (Decomposition_Mapping
property values) are always limited either to a single value
or to a pair. The second character in the pair cannot itself
have a canonical mapping. |
|
Unicode
2.0.0+ |
Canonical
mappings (Decomposition_Mapping
property values) are always limited so that no string when normalized
to NFC expands to more than 3× in length (measured in code units). |
|
Unicode
2.1.3+ |
The
General_Category property values
will not be further subdivided. |
|
Unicode
3.0.0+ |
The
Bidi_Class property values will
not be further subdivided. |
|
Unicode
3.0.0+ |
Once a
character is assigned, its Canonical_Combining_Class
will never change. |
|
Unicode
3.0.1+ |
The
Case_Folding property value is limited
so that no string when case folded expands to more than 3× in
length (measured in code units). |
|
Unicode
3.1.0+ |
The
Noncharacter_Code_Point property
is an immutable code point property, which means that its property
values for all Unicode code points will never change. |
|
Unicode
3.1.0+ |
Once a
character is ID_Continue, it must
continue to be so in all future versions. |
|
Unicode
3.1.0+ |
If a character
is ID_Start then it must also be
ID_Continue. |
|
Unicode
3.1.0+ |
Once a
character is ID_Start, it must continue
to be so in all future versions. |
|
Unicode
3.1.0+ |
Once a
character is XID_Continue, it must
continue to be so in all future versions. |
|
Unicode
3.1.0+ |
If a character
is XID_Start then it must also be
XID_Continue. |
|
Unicode
3.1.0+ |
Once a
character is XID_Start, it must
continue to be so in all future versions. |
|
Unicode
4.0.0+ |
The property
values for the Bidirectional properties
Bidi_Class and Bidi_Mirrored
preserve canonical equivalence. |
|
Unicode
4.0.0+ |
The set
of characters having General_Category=Nd
will always be the same as the set of characters having
Numeric_Type=de. |
|
Unicode
4.0.0+ |
Once a
character is assigned, its Decomposition_Mapping
will never change. |
|
Unicode
4.1.0+ |
All characters
with the Lowercase property and all characters with the Uppercase
property have the Alphabetic property. |
|
Unicode
4.1.0+ |
If a character
is ID_Continue then it must be neither
Pattern_Syntax nor
Pattern_White_Space. |
|
Unicode
4.1.0+ |
The
Pattern_Syntax and
Pattern_Whitespace properties are
immutable code point properties, which means that their property
values for all Unicode code points will never change. |
|
Unicode
4.1.0+ |
If a character
is XID_Continue then it must be
neither Pattern_Syntax nor
Pattern_White_Space. |