This Rhino Script allows the user to select multiple layer names and add a prefix to it. It is rather convenient within Rhino since no two layers, including sub-layers, can the same name.

Rhino Script

Option Explicit
'Script written by <David Mans>
'Script copyrighted by <NeoArchaic Studio>
'Script version Tuesday, December 02, 2008 9:25:59 AM

Call Main()
Sub Main()
	Dim arrLayers,layers, prefix
	
	arrLayers = Rhino.LayerNames(True)
	
	layers = Rhino.MultiListBox(arrLayers, "Select Layers")
	If isNull(layers) Then Exit Sub
	
	prefix = Rhino.StringBox("Type Prefix")
	If isNull(prefix) Then Exit Sub
	
	Dim i
	
	Call Rhino.EnableRedraw(False)
	
	For i = 0 To uBound(layers) Step 1
		Call Rhino.RenameLayer(layers(i), prefix &amp; layers(i))
	Next
	
	Call Rhino.EnableRedraw(True)
End Sub