File label HDR3 for magnetic tapes

The HDR3 label is never written as part of initialization. If it exists, however, it is output when the labels are read.

Byte no.	Field name	Length	Field contents
1 - 3	Label name	3	HDR
4	Label number	1	3
5 - 12	Owner ID <uid>	8	xxxxxxxx
13 - 56	File name <fnam>	44	xxx...xxx
57 - 60	Read password <rpass>	4	xxxx or X' 00000000'
61 - 64	Write password <wpass>	4	xxxx or X' 00000000'
65 - 68	Execution password <epass>	4	xxxx or X' 00000000'
69	Access type <acc>	1	0 = read + write 1 = read only
70 - 80	- reserved -	11	_..._

H	D	R	3	uid								fnam
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
fnam
17	18	19	20	21	22	23	24	25	26	27	28	29	30	31	32
fnam
33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48
fnam								rpass				wpass
49	50	51	52	53	54	55	56	57	58	59	60	61	62	63	64
epass				acc	_	_	_	_	_	_	_	_	_	_	_
65	66	67	68	69	70	71	72	73	74	75	76	77	78	79	80