Found this discussion in other Forums twice. The Members came to the same conclusion, that
B.D.III seems to be an abbreviation for „
Bekleidungs-Depot III“. The Number 147 seems to be an ID for the object (in this case a Pickelhaube). Other numbers have been multiple found on same objects and could be identified (Object-List below is copied from Link „Discussion 2 (on feldgrau-forum.com)“)
Discussion 1 (on gmic.co.uk)
http://gmic.co.uk/topic/11853-bak/
Discussion 2 (on feldgrau-forum.com) This one is well explained and discussed, unfortunately in german...
https://www.feldgrau-forum.com/threads/kammerstempel.26150/page-2
Object-ID-List
78 B.D.III - 1915 Pickelhaube
102 B.D.III - 1917 Tornister
143 B.D.III - 1917 Tornister Schulterriemen
147 B.D.III - 1916 Pickelhaube
149 B.D.III - 1915 Pistoletasche M-08
149 B.D.III - 1915 Patronentasche M-09
154 B.D.III - 1915 Patronentasche M-09
200 B.D.III - 1917 Tarnband
201 B.D.III - 1917 Tarnband
201 B.D.III - 1915 Halsbinde
249 B.D.III - 1916 Mantel M-16
262 B.D.III - 1916 Brotbeutel
265 B.D.III - 1916 Tarnband
275 B.D.III - 1915 Unterhosen, Trikot (11.J.R.)
292/37 B.D.III - 1916 Bluse
301 B.D.III - 1918 Brotbeutel
331 B.D.III - 1916 Tornister
349 B.D.III - 1917 Mantel M-16