Syntax rules for GTFPARM

The following rules apply to the creation of a GTF parmlib member:

Specify the TRACE keyword and its main options only on the first record. Do not place them on subsequent records. For example,
```
Record #1:      TRACE=IOP,SVCP,SSCH
```
This example requests the tracing of specific I/O interrupts, specific SVC interrupts, and all start subchannel and resume subchannel operations.
The second and subsequent records should contain only “prompting” keywords, such as IO= or SVC=. These keywords provide for detailed operands that indicate which I/O interrupts or which SVC interrupts should be traced. For example, the IOP and SVCP keywords in the Record #1 example (above) must be followed by prompting records that name specific device numbers and specific SVC numbers for which interrupts should be traced. As an example,
```
Record #2:     IO=(191,192,102A),SVC=(1,2,3)
```
If the specific operands of any prompting keyword are missing, GTF does not prompt the operator. It accepts a general specification. For example, if IOP is specified in Record #1, and Record #2 specifies only SVC=(1,2,3), and no particular device numbers are specified for I/O tracing, GTF assumes that tracing of I/O interrupts is desired for all devices.

When all of the records have been read, GTF issues message AHL103I TRACE OPTIONS SELECTED -- IO,SVC=(1,2,3). The operator can then respond to message AHL125A RESPECIFY TRACE OPTIONS OR REPLY U by either entering all the desired options or accepting the input that was specified in the parmlib member.
An END keyword or an end-of-file must follow all prompting keywords. If the END keyword is used, it must appear either on the last record supplying prompting keywords or on its own record.
Lines that begin with an asterisk in column 1 are comments.
If you need to specify additional operands for the same keyword, restate the keyword and the additional operands in a subsequent prompting record. The previous examples, expanded to include additional SVC numbers and an END keyword, would appear like this:
```
Record #1:      TRACE=IOP,SVCP,SSCH
 
Record #2:      IO=(191,192,102A),SVC=(1,2,3)
 
Record #3:      SVC=(4,5,6,7,8,9,10),END
```
Certain trace options do not work in combination with others. Table 1 shows those trace options that should not be specified together. If you specify two or more options from the same horizontal row, GTF uses the option in the lowest numbered column and ignores the other options. For example, if you specify both SYSP and SVC (row C), GTF uses SYSP and ignores SVC.

Table 1. Combining certain GTFPARM options
	1	2	3	4	5
A	SYSM	SYSP	SYS	SSCHP	SSCH
B	SYSM	SYSP	SYS	IOP	IO
C	SYSM	SYSP	SYS	SVCP	SVC
D	SYSM	SYSP	SYS	PIP	PI
E	SYSM	SYSP	SYS	EXT
F	SYSM	SYSP	SYS	RR
G	SYSM	SYSP	SYS	CSCH
H	SYSM	SYSP	SYS	HSCH
I	SYSM	SYSP	SYS	MSCH
J	SYSM	SYSP	SYS	XSCH
K	URSP	USR
L	CCWP	CCW