CA Jclcheck Runtime options affect a wide range of input, processing, and output functions. Each installation has its own set of defaults, and with each execution of CA JCLCheck you can change the defaults or options for that run. As the initiation of processing begins, CA JCLCheck evaluates the options in effect for that execution. CA JCLCheck Reference Guide reports the explanation of all these Options. 
Below the CCLIST Option explanation:

CCLIST option requests a listing of the first few cards of every input stream data set (such as utility control statements). The listing appears on the Listing of Merged JCL Report, Report #2. This option has the following format:

CClist[(number-of-cards)]|NOCClist

number-of-cards
(Optional) Specifies the number of cards to print. 
Default: CClist(5)
Limits: 999

Despite this description, it happens that if a customized  CAZ1REXX analyses in RAW_PROCESSING section a //SYSIN that contains more than 999 lines and CCLIST(999) is set,  then only 999 in-stream lines are passed to the rexx to be validated. 
How to correct this behavior with more than 999 in-stream lines? 
 
 

Z/OS - JCLCheck 

It has been verified into the product code that the maximum value accepted for CCLIST option is 32767 so the documentation will be corrected according to that.
In addition it should be underlined that the CTLSCAN option controls how many records are read and kept in storage, so the CCLIST option not only affects reports, but it will also limit the number of records passed to REXX procedures.
That's why it is necessary to specify CC(32767) if you want to insure that all control cards will be passed to REXX.