|This page in a nutshell: Mobile edits with misleading edit summaries probably were not intended to deceive patrollers.|
Canned edit summary is a feature that allows users to quickly insert common edit summaries for their contributions. This feature is available as part of the standard browser-based editor in some versions of Wikipedia (such as the Russian and Chinese editions, but not including the English edition), as well as Wikipedia's mobile application, which can be used on any edition. Before a user saves their edit, they may press one or more of the on-screen buttons, each representing a commonly used edit summary. These options may include "Fixed typo", "Fixed grammar", or "Added links", among others, depending on the wiki in which it is used.
While this is a convenient feature for users, some may click or tap the buttons simply because the buttons are there, or perhaps they think they have to select one (i.e., they believe the edit will not be saved unless they enter a summary, which is not true). Consequently, one may see a substantial edit with the summary "Fixed typo" or other misleading summary. Patrollers should be careful not to assume the edit summary was intentionally misleading or that the edit was made in bad faith.
As an added measure to help with identifying and dealing with vandalism and other disruptive edits, an automated filter adds the tag canned edit summary to these types of edits made on the English Wikipedia. As the web-based editor does not offer canned edit summaries, these edits should also have the tags Mobile app edit or Mobile web edit in addition to Mobile edit (see Wikipedia:Tags and Special:Tags).
Even though there is no edit summary feature enabled by default on English Wikipedia, there is an optional feature that users can turn on that provides drop-downs with canned edit summaries. This feature can be turned on by going to the gadget tab of the preferences and checking off "Add two new dropdown boxes below the edit summary box with some useful default summaries" under the Editing section.