Many thanks, TIG. I don't know anything about ruby language (that is, I don't know how to program in ruby), but I'll sure give it a try.
The real layer names are more like:
Aqua - Payload Vertical
Aqua - Payload Horizontal
Aqua - Tilt Fixture
Aqua - Simple Stand
etc......
Walls
Floor
Ceiling
etc......
Those with a prefix are unique to the current scenario: those without a prefix are "standard" for all scenarios.
So, if I understand your approach, I would first strip off the prefixes, then add the new one.
"txt1 = "Aqua -"; "txt2=""; layer.name=layer.name.gsub(txt1,txt2)]"
Would this strip the Aqua prefix and ignore those without that prefix?
How would I then change the prefix (to only those that had the Aqua prefix before) to "Jason"?
How would it deal with layers that did not have a prefix (or had some other prefix)?
Are there some ruby commands that would do something like (with txt_oldprefix and txt_newprefix being inputs):
txt_oldprefix = "Aqua"
txt_newprefix = "Jason"
LOld = Len(txt_oldprefix)
LName = Length(layer.name)
If (left(layer.name,LOld) = txt_oldprefix,then layer.name = txt_newprefix + right(layer_name,LName-LOld))
Maybe I'm just too dense and should continue going through each layer name and change it by cut and add. It's just such a bummer when there are twenty-something affected layers