Instrumentation Categories

The first  two digits of the product code for each piece of sheet music indicates its instrumentation category. 
i.e. 01C030001605 is the code for Poulenc's Sonata for flute & piano. The bold digits (01) indicate the instrumentation category. See below.

01 - Flute & Piano
02 - Cadenzas
03 - Flute Alone
03A - Flute Alone (Collection Books)
04 - 2 Flutes
04A - 2 Flutes (Collection Books)
05 - 2 Flute & Piano
05A - 2 Flutes & Piano (Collection Books)
06 - 3 Flutes
06A - 3 Flutes & Piano (Collection Books)
07 - 3 Flutes & Piano
08 - 4 Flutes
08A - Flute Flutes (Collection Books)
09 - 4 Flutes & Piano
10 - Flute Choir
10A - Flute Choir (Collection Books)
11 - Flute & Bassoon
12 - Flute & Clarinet
13 - Flute & Tape/CD
14 - Flute & Guitar
14A - Flute & Guitar (Collection Books)
15 - Flute & Harp
15A - Flute & Harp (Collection Books)
17 - Flute & Organ
17A - Flute & Organ (Collection Books)
18 - Flute & Percussion
19 - Flute & One Wind
20 - Flute & Two Winds
20A - Flute & Two Winds (Collection Books)
21 -  Flute & One String
21A - Flute & One String (Collection Books)
22 - Flute & Two Strings
23 - Flute, One Wind & One String
24 - Flute, One Wind & Piano
25 - Flute, One String & Piano
27 - Woodwind Quartets
27A - Woodwind Quartets (Collection Books)
28 - Flute, Two Strings & Piano
29 - Flute & Three Strings
30 - Mixed Quartets (Winds & Strings)
30A - Mixed Quartets (Winds & Strings - Collection Books)
31 - Mixed Ensembles (5 or more Instruments)
31A - Mixed Ensemble Collections
33 - Woodwind Quintets
33A - Woodwind Quintets (Collections)
34 - Flute & Voice (with and without accompaniment)
35 - Miscellaneous Ensembles
36 - Flute with Band or Orchestra
37 - Alto Flute & Bass Flute (with and without accompaniment
38 - Piccolo (with and without accompaniment)
39 - Irish Flute, Pennywhistle, Tin Whistle, Fife, Pan Flute, Ocarina
40 - Flute & Piano Collection Books
41A - Christmas & Hanukah Music - One Flute (with and without accompaniment)
41B - Christmas & Hanukah Music - Two Flutes (with and without accompaniment)
41C - Christmas & Hanukah Music - Three Flutes (with and without accompaniment)
41D - Christmas & Hanukah Music - Flute Flutes (with and without accompaniment) 
41E - Christmas & Hanukah Music - Flute Choir (with and without various instruments)
42 - Blues, World, Jazz, Pop, Rock
43A - Sacred - One Flute (with and without accompaniment)
43B - Sacred - Two Flutes (with and without accompaniment)
43C - Sacred - Three Flutes (with and without accompaniment) 
43D - Sacred - Four Flutes (with and without accompaniment)
44 - Methods & Studies
45 - Fingering Charts
46 - Orchestral Excerpts
46A - Kalmus First Flute Folders
46B - Megido Complete Orchestral Parts
47 - Native American Flute
48 - Literature (Books, etc.)