If you put the # character before any entry in the list of sites it will be ignored. This can be useful for temporarily deactivating entries in the list. You can also use # to insert comments, but note that comments cannot include the space character, so use another character (e.g., underscore) instead.

Note also that if “Sort the list of sites” is selected, any entries starting with # will be moved to the top of the list, because LeechBlock will sort the list in alphanumerical order.