Each word list has an associated letter mapping that defines which letters are equivalent. For example, in most puzzles upper case and lower case letters are treated as equivalent. In many countries accented letters are also equivalent to the unaccented letters for the purpose of intersecting words in crosswords. Thus if é is defined as equivalent to E, any word containing the letter é will appear in the grid with E substituted for é.
Use the Equivalent letters option on the Word List Manager’s Word List menu to define which letters in a word list are equivalent. You can also choose the appropriate mapping whenever you make a new word list.
Each line in the letter mapping is of the form A=B, or ABC=D, where you want the latter A to be mapped to B, or all the letters ABC to be mapped to D.
Click the Set all accents equivalent to map all accented letters to their unaccented forms. Click Map all letters to upper case if you just want to map letters to their uppercase equivalents. If the box is black, all letters will be distinct, so grid fills will be case-sensitive.
The Punctuation tab can be used to fine-tune which non-letter characters are removed from words before inserting in the grid. Spaces are always removed, but here you can select which other characters to ignore. Unless you want to use some punctuation symbols for special purposes, you can probably use the All punctuation option.
The characters that are allowed in the list depends on the word list's character set.