Here are some other possibilities, depending on the context:
* "Tees" - This is a shorter, more informal abbreviation.
* "Bd. of Trs." - This is a more formal abbreviation, used for "Board of Trustees."
* "Trs. of [Name of organization]" - This is another formal abbreviation, used to specify the organization the trustees are associated with.
The best abbreviation to use will depend on the specific context and your audience.