| • The combine-char feature allows character-combination-declarations. |
| • The keyword feature allows #!key in formal-argument-lists. |
| • The multi-source feature allows use of the transform-grove procedure. |
| • The multi-result feature allows multiple result groves. |
| • The regexp feature allows the use of node regular expressions described in section 10.3.2, Node Regular Expressions. |
| • The word feature allows the use of the facilities for word searching described in section 10.3.1, Word Searching. |
| • The hytime feature allows the use of the facilities for HyTime location addressing described in section 10.2.1, HyTime Support. |
| • The charset feature allows the use of the declaration element type forms other than char-repertoire, features, and sgml-grove-plan. |