tcl-itcl4-doc binary package in Ubuntu Focal riscv64

 [incr Tcl] (or itcl) is a popular object-oriented extension for the
 embeddable Tcl scripting language. The name is a play on C++, and
 itcl has a similar object model, including multiple inheritance and
 public and private classes and variables. Unlike most OOP extensions
 to Tcl, itcl is written in C for speed.
 .
 This package contains the man pages for the new commands that itcl
 adds to Tcl.

Source package