Creating a custom collating sequence file

Determine whether there are any ligatures. A ligature is a single character that is sorted as multiple characters. If there are ligatures:

• Place the ligature (“lig”) entries together, preceding the “char” entries.

• Include both the uppercase and lowercase forms of a ligature, if applicable.

The syntax for a case-sensitive ligature is:

lig = value, after characters ;case-sensitive sort

where:

• characters is a string representing the characters after which the ligature will sort.

• value is the hexadecimal encoding for the ligature character, or the typed or quoted ligature character.

The syntax for a ligature that is not case sensitive:

lig = value1=value2, after characters ;case-insensitive sort

where:

• value1 and value2 are the hexadecimal encodings for the uppercase and lowercase ligature characters, or the typed or quoted ligature characters.

• characters is a string representing the characters after which the ligature will sort.

The following example shows ligature entries in a collating sequence file that is not case sensitive for ISO 8859-1:

lig = 0xC6, after AE ;diphthong AE, A with E

lig = 0xE6, after ae ;diphthong ae, a with e

char = 0x41,0x61,0xC0,0xE0,0xC1,0xE1,0xC2,0xE2x

;varieties of letter A

char = 0x42,0x62 ;B, b

. . .

Vertically list all the character entries for the sort order. This vertical list is the primary sort order.

The syntax for a character entry is:

char = value

where value is the hexadecimal code set encoding for the character, or the typed or quoted character.

For example:

char = 0x41					;ISO 8859-1 code set.

If applicable, add secondary sort order information to the file as follows:

• For a case-sensitive sort order, put the lowercase variant to the right of the uppercase character (if you want the uppercase character to take precedence). Separate the characters with the list separator character.

• For a sort order that is not case sensitive, put equal signs between each uppercase character and its lowercase equivalent (including accented characters).

• Put a character and its variants in relative order to each other. For example, the French “é” goes to the right of “e.” Make sure these characters are not ligatures or separate primary sort order entries. Separate variants with the list separator character.

The following example shows secondary sort order information for a Latin alphabet, case-sensitive sort order:

char = 0x41,0x61,0xC0,0xE0,0xC1,0xE1,0xC2,0xE2,

0xC3,0xE3,0xC4,0xE4,0xC5,0xE5

;A, a, A-grave, a-grave, A-acute, a-acute, 

;A-circumflex, a-circumflex, A-tilde, a-tilde,

;A-diaeresis, a-diaeresis, A-ring, a-ring

. . .

char = 0x4E,0x6E,0xD1,0xF1 ;N, n, N-tilde, n-tilde

. . .

Determine whether there are any sort doubles. A sort double or digraph is a pair of characters that is sorted as a single character. If there are any sort doubles:

• List each sort double as a separate “char” entry.

• For case-sensitive sorting, put all permutations of the sort double in the desired sort order.

The syntax for a sort double is:

char = value1value2

where:

• value1 is the first character in the sort double pair,

• value2 is the second character in the pair.

If value1 and value2 are written as hexadecimal numbers, use a leading ‘0x’ with value1 but not with value2. For example:

char = 0x4348,0x4368,0x6348,0x6368 ;CH,Ch,cH,ch

value1 and value2 can also be typed or quoted characters. For example:

char = CH, Ch, cH, ch

or

char = "CH", "Ch", "cH", "ch"

The following example shows the placement of the Spanish sort double “ch” in a case-sensitive .srt file for the iso_1 (ISO 8859-1) character set:

char = 0x41,0x61,0xC0,0xE0,0xC1,0xE1,0xC2,0xE2

;varieties of letter A

char = 0x42,0x62 ;B, b

char = 0x44,0x64,0xC7,0xE7 ;C, c, C-cedilla, c-cedilla

char = 0x4348,0x4368,0x6348,0x6368 ;CH,Ch,cH,ch

. . .