All fields in all files are tab-delimited and wrapped in double
quotes.  Each record consists of a single line, terminated by a
newline.  When possible, fields are identified only by their position
in the file, while others are identified by a tag followed by an "=".

There is the concept of "next quarter" and "previous quarter" (but not
"current quarter"!).  The next quarter is determined by locating the
greatest-named subdirectory matching the pattern "YYYY[wi,sp,su,au]".
The "previous" quarter is the one before the "next" one. E.g. writing
in November, 1997, "1998wi" exists, so the next quarter is "Winter,
1998" and the previous quarter is "Autumn, 1997".

Graduate student submissions go into the file "grad.txt".  The fields are:

  Pos Name       Value
  1   login
  2   first name
  3   last name
 *4   status     [I,A] == [inactive,active]
 *5   teach      [Y,N,C,A,] == [yes,no,cannot,no preference,not specified]
 *6   position   [F,R,E,] == [TAonly,TA/RA only,not specified]
  7   comment
  8-N rating     [1-5] e.g. "321=4"

 *Changed Spring, 1998.

Undergraduate submissions are in "ugrad.txt".

  Pos   Name                Value
  1     login
  2     first name
  3     last name
 *4     status              [I,A] == [inactive,active]
  5     class               Frosh, Soph, Junior, Senior (if status is I)
  6     major               [CS,CE,Other] (if status is I)
  7     comments
 *8     experience          [T,G,] == [TAed,graded,unspecified]
  9     consider            [T,E,G] == [TA, either, grader]
  9-N   rating              [1-5]

 *Changed Spring, 1998. Many fields retired.

TA selection goes to ta_request.txt.  All fields are positional.

  Pos Name                 Value
  1     instructor         instructor name
  2     course             course number
  3     no_grad            [YN] (Y means she *doesn't* want grad TAs)
  4-6   prefer_grad_[1-3]  TA email address
  7     prefer_grad_other
  8-10  avoid_grad_[1-3]   TA email address
  11    avoid_grad_other   freeform text
  12    no_ugrad
  13-15 prefer_ugrad_[1-3] TA email address
  16    prefer_ugrad_other TA email address
  17-19 avoid_ugrad_[1-3]  TA email address
  20    avoid_ugrad_other  freeform text
  21    comments

TA rating is not implemented yet.