Create index entries.
| Type & position: | placeholder, main part |
| Syntax: | (!idx [<text>] {[<index1>]} {[<index2>]} {[<index3>]}) |
| Description: | Useful for adding indices right inside the source file. |
| Example: | (!idx [word] [index entry]) |
| See also: | Indices, (!index), !no_index, !index |