Use only dictionary characters in text comparisions.

Declare (non)dictionary characters (nondictionary)

Array declaration

Segment Source

 138: /* Table of non-dictionary characters (not letters, digits, or blanks). */
 139: static int nondictionary[UCHAR_LIM];
 140: 

Define (non)dictionary characters

Code insertion

Segment Source

 461:       if (!ISALNUM (i) && !ISBLANK (i))
 462:         nondictionary[i] = 1;

Insert user message text

Text insertion

Segment Source

 223:   -d               consider only [a-zA-Z0-9 ] characters in keys\n\

Parse DictOnly option (-d)

Code insertion

Segment Source

1679:         case 'd':
1680:           key->ignore = nondictionary;
1681:           break;