The Rulesets Page contains all of the settings for controlling how Rulesets are used by DiffMerge. For information about the contents of an individual Ruleset, see Rulesets.
Rulesets allow you to fine-tune DiffMerge to handle different types of files. This includes things such as character encodings, end of line conventions, and whitespace handling.
The Restore Defaults button restores all the fields on this (and only this) page to their original factory settings. This will also delete all of your Rulesets and restore the original set of Rulesets that were originally shipped with the program.