SF-LPC flags
------------
A - auto-processing (default)
S - step-processing (S = S1)
    S# - Step Processing and level of (optional). (levels yet to be determined)
I - interactive mode = S0 (Step processing is inherently interactive but at '0' 
    level SF processing doesn't step, but only prompts user for a SF line to 
    process when it has nothing to do. It does not step in processing the line.)
 
E - enable SF (default)
B - bypass SF processing (IQ and ID out is directly to OP setting direction)
D - disable SF processing (Suspends SF leaving only AI processing available)

+/- (V)ariables: +V process VIC variables (default), -V don't process VIC variables
+/- (C)ommands: +C process VIC commands (default), -C don't process VIC commands

T filename  - tee to file (Append to file)
R filename  - redirection to file (Append to file)

---------------------------------
Positions:
1-    2    3    4     5   6-----------
=================================================
A(-)  E(-) V(+) C(+) (-)  -------(32 char)-------
S#    B    -    -     T - filename
I     D               R - filename
-------------------------------------------------
Default value:
--   -   +   +  - ---

Example:
S2 B + + T teefile