Dummy edit 
A dummy edit is a change in wikitext that has little or no effect on the rendered page, but saves a useful dummy edit summary. The dummy edit summary can be used for text messaging, and correcting a previous edit summary such as an accidental marking of a previous edit as "minor" (see Help:Minor edit). Text messaging via the edit summary is a way of communicating with other editors. Text messages may be seen by dotted IP number editors who don't have a user talk page, or editors who haven't read the subject's talk page, if it exists. Each edit summary can hold 202 text characters. A dummy edit should be checkboxed "minor" by logged-in editors.
- Changing the number of newlines in the edit text. Changing from 0 to 1 or from 2 to 3 (or vice versa) has no effect on the rendered page. Changing from 1 to 2 newlines makes a rendered difference that may not be a dummy edit. Adding newlines to the end of the article will not save as a dummy edit (see below).
Null edit 
A null edit occurs if a page save is made when the wikitext is not changed, which is useful for refreshing the cache. A null edit will not record an edit, make any entry in the page history, in Recent Changes, etc., and the edit summary is discarded.
- Opening the edit window and saving. A section edit save is sufficient.
- Adding newlines only to the end of the article and saving. This is also a null edit.
See also