### 4.4 Characters

- The number of bits in a byte (C90 3.4, C99 3.6).

  Determined by ABI.

- The values of the members of the execution character set (C90 and C99 5.2.1).

  Determined by ABI.

- The unique value of the member of the execution character set produced for each of the standard alphabetic escape sequences (C90 and C99 5.2.2).

  Determined by ABI.

- The value of a `char` object into which has been stored any character other than a member of the basic execution character set (C90 6.1.2.5, C99 6.2.5).

  Determined by ABI.

- Which of `signed char` or `unsigned char` has the same range, representation, and behavior as “plain” `char` (C90 6.1.2.5, C90 6.2.1.1, C99 6.2.5, C99 6.3.1.1).

  Determined by ABI. The options `-funsigned-char` and `-fsigned-char` change the default. See Options Controlling C Dialect.

- The mapping of members of the source character set (in character constants and string literals) to members of the execution character set (C90 6.1.3.4, C99 6.4.4.4, C90 and C99 5.1.1.2).

  Determined by ABI.

- The value of an integer character constant containing more than one character or containing a character or escape sequence that does not map to a single-byte execution character (C90 6.1.3.4, C99 6.4.4.4).

  See Implementation-defined behavior.

- The value of a wide character constant containing more than one multibyte character, or containing a multibyte character or escape sequence not represented in the extended execution character set (C90 6.1.3.4, C99 6.4.4.4).

  See Implementation-defined behavior.

- The current locale used to convert a wide character constant consisting of a single multibyte character that maps to a member of the extended execution character set into a corresponding wide character code (C90 6.1.3.4, C99 6.4.4.4).

  See Implementation-defined behavior.

- The current locale used to convert a wide string literal into corresponding wide character codes (C90 6.1.4, C99 6.4.5).

  See Implementation-defined behavior.

- The value of a string literal containing a multibyte character or escape sequence not represented in the execution character set (C90 6.1.4, C99 6.4.5).

  See Implementation-defined behavior.