SCL can be converted to STL, but not STL to SCL. The OP codes display in the language selected, that is true with all programs. The comments and symbol table stay as they were. You can copy and paste them to Excel, edit them and return them. This would allow OEM's to have comments and symbols in multimple languages. You must keep the same cell format. Check out the attached demo and you will see what I ment in the SCL to STL. If you remove the // in front of Know_How_Protect, it is protected. I do know the back door to unprotect them though. It keeps the honest people honest. You will notice that from the outside of the block, LAD, STL, SCL, etc all look the same. If you were to KHP the blocks, you would have to look at the block properties to see what they were developed with.