There is another way also.
You have the option of three places to display the custom field:
- Before Message
- After message
- Thread Status block
If you intend to never use any one of these positions, you can just hide that specific position.
So for example I never use the
After message position. Any fields I don't want displayed I use that, and then the one piece of code covers them all:
Code:
.message-fields--after
{display:none}