This is a slightly modified list taken from [SGML-Tools User's Guide 1.0 ($Revision: 1.1.1.1 $)]. If you miss some, don't hesitate to mail. A lot of the named characters shown in table Named Characters are same as in the html-dtd.
There is a small number of whatever you want to name it. The look like named characters, but will be printed not always, or not at all.
Thin space:
d D ->d D
Emphasized space: d D -> d D
Normal space: /d D/ -> d D
No break space: A spaces at wich the line is not allowed to be broken. Two words separated by a nbsp will be treated by parser and mapper to be a single long one.
Suggest Hyphen: If the mapper is up to break a word, with has the shy tag inside, it will probably do the wordbreak at the place of the shy tag and place a hyphen instead. If no wordbreak is necessary the shy expands to nothging at all.