I don't know what you are seeing in mohamed's reply. Let me show you the reply.
Mohamed wrote :
Yes you can change the description of a tax code.
Execute Tcode FTXP, select the tax code you wish to change with the associated procedure andr jurisdiction code as if you plan to make a rate change. Then select "GoTo ->Properties" from the top menu. It will open up the description field for modification. Make the change and save it. Once you re-enter the tax code again, it will appear with the new description.
Now leave the B1 or A1. Just compare this reply with Prasoon's reply and tell me the differences between these two replies.