Incorrect.
:x is a vi feature, that was introduced by Mary Ann Horton to actual Joy+Horton vi in February 1980.
* https://code.illumos.org/plugins/gitiles/illumos-gate/+/refs...
Ritter's vi is derived from Joy+Horton vi. Illumos has the original.
:x is a vi feature, that was introduced by Mary Ann Horton to actual Joy+Horton vi in February 1980.
* https://code.illumos.org/plugins/gitiles/illumos-gate/+/refs...
Ritter's vi is derived from Joy+Horton vi. Illumos has the original.
Of them, and discounting the extreme fringes like vi-likes that run on the BBC Micro, only STEVIE lacks :x, and its derivatives all added it in. All of the other clones from MKS onwards, even neatvi and nextvi, have :x .