Comments.

Comments are stored at offset Header.comments_offset from the start of the file. Lines in this section are of the format:

<Field-ID>=<Value>

<Field-ID> can be any string, though several have special meaning and their use is encouraged.

ID      Field                           Example
MACH    Sequencing machine model        MACH=Pharmacia A.L.F.
TPSW    Trace processing software       TPSW=A.L.F. Analysis
          version                         Program, Version=1.67
BCSW    Base calling software version   BCSW=A.L.F. Analysis
                                          Program, Version=1.67
DATF    Data source format              DATF=AM_Version=2.0
DATN    Data source name                DATN=a10c.alf
CONV    Format conversion software      CONV=makeSCF v2.0

Other fields might include:

ID      Field                           Example
OPER    Operator                        OPER=sd
STRT    Time run started                STRT=Aug 05 1991  12:25:01
STOP    Time run stopped                STOP=Aug 05 1991  16:26:25
PROC    Time processed                  PROC=Aug 05 1991  18:50:13
EDIT    Time edited                     EDIT=Aug 05 1991  19:06:18
NAME    Sample name                     NAME=a21b1.s1
SIGN    Average signal strength         SIGN=A=56,C=66,G=13,T=18
SPAC    Average base spacing            SPAC=12.04
SCAL    Factor used in scaling traces   SCAL=0.5
ACMP    Compression annotation          COMP=99,6
ASTP    Stop annotation                 STOP=143,12

/*
 * Type definition for the comments
 */
typedef char Comments[];                /* Zero terminated list of
                                           \n separated entries */