Solution : https://service.sap.com/sap/support/notes/302655 (SAP Service marketplace login required)
Key words : 
activate checkbox 'expand imm, additional key words sapscript, copy protected text lines, error message td265, attached correction instruction, text area <cntl-, sapscript pc editor, protected text lines, locked text lines, goto--> change editor
Related Notes : 
       
| 396958 | SAPscript: Inserting Clipboard deletes locked text lines | 
| 363243 | SAPscript: Collective note for template lines | 
| 337373 | SAPscript: copy locked texts to clipboard | 
| 305856 | SAPscript: Locked text lines deleted | 
| 302319 | SAPscript: Locked text lines can be edited | 
| 216488 | SAPscript: Incorrect format of locked rows | 
| 215591 | SAPscript: Deletion of locked lines in PC editor |