The QLF file format is inherited from the GTK1 version of quicklist and is likely to be replaced by an XML backend in the GTK2 version.
The following documentation of the QLF file format is copied from the GTK1 version unchanged.
Old file format on disk QUICKFILE 0.0.1 3/6/99 8 3 2 1 0 0 QUICKFILE Identifies file type 0.0.1 Version number 3/6/99 Date file written 8 Fields in file (really 8 fields, not 9) 3 Sort records in file (really 3, not 4) 2 Filters in file (likewise) 1 Reports in file (likewise) 0 Unused 0 Unused FIELD 1 0 0 2 2 18 0 0 Payee (This is first field, stored in [0] 1 Field type (1: alpha, 2: numeric, 3: date, 4: time) 0 Formatting code (n/a for alpha)(style for others) 0 Sub formatting code (n/a for alpha, decimal places for 2) 2 Justification in clist (0: left 1: center, 2: right) 2 Appears in clist column 2 (range is 0...n-1) 18 Width of clist column, in characters 0 Unused 0 Unused Payee is clist column heading FIELD 3 1 0 0 0 9 0 0 Date FIELD 2 1 0 0 1 7 0 0 Check No. FIELD 2 2 2 0 3 11 0 0 Amount FIELD 1 0 0 0 4 10 0 0 Trade FIELD 1 0 0 0 5 10 0 0 Type work FIELD 3 1 0 0 6 9 0 0 Date clear FIELD 2 1 0 0 7 7 0 0 GL Account SORT 0 0 Check number\2 1 0 Unused 0 Unused Then name of sort 2 Field for primary sort (ie, Check No.)(0..n-1) 1 Ascending (0 is descending) SORT 0 0 GL account\7 1 2 1 0 Unused 0 Unused Then name of sort 7 Field for primary sort (ie., GL account)(0..n-1)) 1 Ascending 2 Field for secondary sort (Check no.)(0..n-1) 1 Ascending SORT 0 0 Payee\0 1 2 1 FILTER 0 0 Reconcile\6 1 2/27/99 0 Multiple filters are ORd 0 Unused Reconcile is name of filter 6 Field to check (Date clear)(0..n-1) 1 Type of compare ("equals") 0 Unused 0 Unused 2/27/99 What to compare to FILTER 1 0 Outstanding\6 12\3 4 0 1 AND 0 Unused Outstanding is name of filter 6 Field to check (Date clear)(0..n-1) 12 Type of compare ("is blank") (comparison data not needed 0 Unused 0 Unused 3 Field to check (Amount)(0..n-1) 4 Type of compare (is greater than) 0 U used 0 Unused 0 Comparison data (zero) COLUMN 1 10 0 0 0 0 1 Data base field (Date)(0..n-1) 10 Width of display (in characters) 0 Don't group on this column 0 Don't take a total on this column 0 Unused 0 Unused COLUMN 2 6 0 0 0 0 2 Data base field (Check number)(0..n-1) 6 Width of display (in characters) 0 Don't group on this column 0 Don't take a total on this column 0 Unused 0 Unused COLUMN 0 20 1 0 0 0 0 Data base field (Payee)(0..n-1) 20 Width of display (in characters) 1 Take a group total when this column changes 0 Don't take a total on this column 0 Unused 0 Unused COLUMN 3 11 0 1 0 0 3 Data base field (Amount)(0..n-1) 11 Width of display (in characters) 0 Don't group on this column 1 Take a total on this column 0 Unused 0 Unused REPORT 0 1 0 0 Checks not yet cleared\Header\Footer This report header is for the preceding COLUMN definitions 0 Sort rule (Check number) (Negative number: none) 1 Filter (Outstanding)(Negative number: none) 0 Unused 0 Unused Report name: Checks not yet cleared Header: Up to 80 characters at top of each page Footer: Up to 80 characters at end of each page COLUMN and REPORT can be repeated DATA 0 0 DATA Beginning of data records 0 Unused 0 Unused 7/11/1999\2:00 PM\Joe Blow at Kennedy's 0 Unused 0 Unused 7/1/1999 Field 1 data 2:00 PM Field 2 data Joe Blow.. Field 3 data 9/11/87\\Pay tuition loan