On the Team > Ignored Resources preference page, you can specify file name patterns to exclude from the version control management system. There is a list of file patterns against which resources will be matched before they are considered as version control candidates. These patterns may contain the wildcard characters "*" and "?". This pattern "*" represents any sequence of zero or more characters. This pattern "?" represents any one character. For example, you can specify a pattern of "*~", which would match any temporary files that end with "~". Any file or directory that matches any one of the patterns will be ignored during update or commit operations.
To add a file type to the ignore list, simply click Add Pattern. In the dialog, enter a file type (e.g. *.class). To remove a file type from the ignore list, simply select the file type in the ignore list and click Remove.
You can temporarily disable ignoring the file pattern by deselecting it from the list. You do not have to remove the specified file pattern from the list to temporarily disable it.