Is it possible to protect some parts of ABAP code in Z* programs from any modification? 

Details... I made some templates for rapid ABAP-report design. When I want to create new report, I make copy of template and write some abap code in predefined places. A simplified example: 

report z_my_report. 

perform select_data. 
perform output_data. 

form select_data. 
* Users can place code here 
* >>> 

* <<< 
endform. 

form output_data. 
* Users can place code here 
* >>> 

* <<< 
endform. 

For complex reports it is important than user can write code ONLY in predefined places, not in other program logic. That's because I need to "lock" some parts of abap-code. 

No direct answer for this. 

One solutions is to put the sections of code in a separate include and use the editor lock in the attributes. 

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