Non-canon (also noncanon, uncanonical, uncanon, noncanonical) is content, events, materials or stories that are placed outside of canon, or contradict, ignore, and/or disobey established canon. For example, being out of character is considered to be non-canon.
It is generally accepted that any licensed South Park media without the direct involvement of Trey Parker and Matt Stone is non-canon to the franchise, such as the original three games by Acclaim Entertainment in 1998. However, games made with Parker and Stone's involvement, most notably South Park: The Stick of Truth are considered canon, as confirmed in a Podcast Interview with IGN in 2015.
By default, and any all content created by fans for South Park, including but not limited to fanfiction, fan art and fan characters, is automatically non-canon to the timeline and canon of the South Park television series, however, many authors have their own individual canon which can vary, such as including or excluding certain episodes or spin-off media.