Square land battle flag of Confederate States of America.
Phroziac cut this out of <a href="//commons.wikimedia.org/wiki/File:Flag_of_Mississippi_(2001%E2%80%932020).svg" title="File:Flag of Mississippi (2001–2020).svg">Flag of Mississippi (2001–2020).svg</a>, which is public domain work by Zscout370.
Flag design 1860s, SVG file 2005
This SVG flag includes elements that have been taken or adapted from this flag: