If you wash 'em - do so by hand with a mild detergent.
I'd rather dry-clean.
The reason is because modern soaps will damned near dissolve those old label inks.
The tag'll remain - but that's sort of a moot point.
The numbers are assembly numbers, and some coats had a tag at the rear of the collar.
Incidentally - those aren't crossed swords - they're crossed keys.
They represent the 'keepers' of the Army's stores of equipment.
The nice thing about these cotton uniforms is that they're pretty plentiful and for the most part in good shape - with many actually in 'new' condition.
When worn - the WWI uniform consisted of the wool coat and trousers - wool pull-over shirt, square-tipped mohair tie, undershirt and drawers of 'generally' a wool-cotton blend, web belt and frame buckle, wool socks, wool leg wraps (puttees), low-quarter, roughout 'field shoe w/hobnails and the wool 'Overseas' cap or Campaign Hat when in CONUS.
Put 'that' on and add the large wool trenchcoat, the pack with shelter-half, mess kit, personal clothing, sewing 'housewife' and wool blanket.
Add the cartridge belt, canteen canteen cup and carrier, 16" bayonet and scabbard, First-Aid packet, '03 Springfield w/sling 'and' Gas Mask and carrier.
Now - given all that - and maybe some body lice (cooties) as well as a case of the runs - be sure to soak as much of yourself and your (really water-absorbing wool) gear - put the mask on - wait for the whistle and crawl 'Over the Top' while some honked-off individual behind a Maxim gun sweeps right to left while you're in the process - and try to capture a few yards and live through 'that' bit of high entertainment.
And do it again - tomorrow...
No 'wonder' Grandpa was an irascible old coot...
Vaya,
Scouts Out!