Ethan Merritt - 17 hours ago

Good catch. The documentation for 6.1 includes the text:

A data block acts like an array of strings. Any single line can be accessed
or replaced. For example to replace the first line of an existing data block
with a comment
$Mydata[1] = "# Last plotted " . time("%d-%m-%Y %H:%M:%S")

but I guess that bit of text did not get taken back into the docs for 6.0