(Auszug aus "XSL-FO ― Die Referenz" von Manuel Montero Pineda & Steffen Herkert, 2016, dpunkt.verlag)
Category Spacing and Alignment >> Adding Space
Changes letter-spacing depending on the number of characters. [no-LT]
|Value:||[ none | <length> | <percentage> ]*|
|Applies to:||inline-level formatting objects|
|Percentages:||refer to the font size|
Values have the following meanings.
|none||Does not specify letter-spacing.|
Values can be enumerated corresponding to the number of characters of 2 or more. For example, if specified as follows;
axf:auto-letter-spacing="2em 1em 0.5em 0.25em"
when the number of characters in this FO is 2, then letter-spacing="2em" is applied. When 3 characters, then letter-spacing="1em" is applied. When 4 characters, then letter-spacing="0.5em" is applied. When 5 characters, then letter-spacing="0.25em" is applied. Nothing is done with the other numbers of characters. Only the characters included in the first in-line element is counted.
This property is defined mainly assuming the chapter in CJK. In the following case,
it's better to use axf:letter-spacing-side toghther as follows.
It's not possible to apply this property to the text to which the number of characters (like page numbers, etc.) is not decided.
This property is not available with AH Formatter V6.3 Lite.