Files with rvt suffix can be also found as some kind of source files or scripts for Apache Rivet Tcl.
RVT file extension - Apache Rivet Tcl file
What is rvt file? How to open rvt files?
File type specification:
The rvt file extension seems to be also used for one of the file types from Apache Rivet Tcl, an "umbrella" for Tcl-Apache integration efforts. These projects combine the power of the Apache web server with the capabilities of the mature, robust and flexible Tcl scripting language.