The text read off it
[03.02.03]
The unit specification may be made in any of the following ways:
a) No specification — when the option is not exercised any available unit is to be assigned to the file.
b) m — any available unit of this model type is to be assigned to the file.
c) X — any available unit on this physical channel is to be assigned to the file.
d) P — all files in the job having this symbolic channel designation are to be assigned to the same channel.
e) X(k) — the kth available unit on the specified channel is to be assigned to the file; note that the parenthesis are required.
f) Pm — any available unit of this model type on the symbolic channel specified is to be assigned to the file.
g) Pkm — an available unit on the symbolic channel, having this model number, is to be assigned to the file. k in this use without parenthesis indicates the order of preference for the channel so that if the number of available units on the channel is less than the total requested for the channel those with lower numbers are to be assigned to the same channel.
h) System units may be assigned by:
i. `IN` — the current system Input unit is to contain the file.
ii. `OU` — the current system Output unit is to be used for a printed output file.
iii. `PP` — the current system Peripheral Punch unit is to be used for a punch output file.
iv. `UTk` — System utility tape k (non-parenthesized k = 1-4) is to be used for the file.
i) Card equipment is assigned for a file by:
1) `RDX` — card reader, channel X
2) `PRX` — printer, channel X
3) `PUX` — card punch, channel X