Showspells

showspells is the extended command to view and reorder the spells the hero knows. Default keybinding is +.

See the Spellcasting and spellbook articles for more details.

The menu looks like this:

Currently known spells

    Name                 Level Category     Fail Retention
a - force bolt             1   attack         0%      100%
b - detect food            2   divination    53%      100%
+ - [sort spells]

Selecting a spell allows you to reorder specific spells by swapping the spell with another.

Playing in wizard mode also shows the spell retention in number of turns.