<?= ... ?> — Shorthand construct for single strings output
This construct is a simplified form to print a single string wherever needed in a ?.rvt? template. The contruct is equivalent to writing the following line of Tcl code
puts -nonewline $string
The ?string? argument to the shorthand construct can be any Tcl command returning a value
See Example 1, “Hello World” or Example 3, “Variable Access”