An order by question

All,

I need a little help on a sorting problem. Imagine a table, call it
records, that has fields:

lastName
firstName
term

I want to sort the records by last name, then first name, and finally by
term. This almost does what I want:

select * from records order by lastName, firstName, term;

However, the possible values for term are:

2002F
2003S
2003X
2003F

Where F is for fall, S for spring, and X for summer session. Thus, a
straight alphabetical sort doesn't give me what I want. If the year is the
same, then I want a sort with S, then X, then F for identical year.

Any suggestions?