Comment field on MT4 orders

 
Can somebody confirm or deny if the comment field on the orders (MT4) sometimes is modified (overwritten) by the broker server?

Thank you
 
The only observation I have on the comment field is that the string [tp] is appended once the TP has been hit and the order closed.
The comment field is cleared or replaced by 'cancelled' in cancelled orders.
 
hdb, thank you for your answer. I just noticed that comment field appends [sl] once a S/L is hit.