Hi Tino. Yes, that is correct. This application has variables named like: 'AR-DA-08' This also fails in a Page Template: <span tal:define="standards python: request.SESSION"> <tal:block define="temp python: data.set('AR-DA-08',AR-DA- 08)"></tal:block> </span> With the error: Compilation failed TAL.TALDefs.TALError: Python expression error: invalid token (Python expression "data.set('AR-DA-08',AR-DA-08)", line 1) in expression "python: data.set('AR Yet this works: <span tal:define="standards python: request.SESSION"> <tal:block define="temp python: data.set('AR-DA-07',AR-DA- 07)"></tal:block> </span> So you are saying the interpreter is seeing the '-' as a minus? Why would it work in one case and not the other? Could the minus be escaped somehow? -- Harlow Pinson Indepth Learning Email: hpinson@indepthl.com Phone: 505 994-2135 Fax: 505 994-3603