Article 133570 of comp.os.vms:

 Potential system crash when using SYMBOL V4.0 on OpenVMS VAX V7.1 
 -----------------------------------------------------------------

*** NOTICE *** 
--------------
If you are using the SYMBOL V4.0 release (SYMBOL040-97143) which was 
distributed on the Spring 1997 DECUS OpenVMS collection and you have
plans to install it on or up upgrade to OpenVMS VAX V7.1, you should
contact me at VAXman@TMESIS.COM for an update for SYMBOL which fixes
a problem under OpenVMS VAX V7.1.

PROBLEM DESCRIPTION
-------------------
Digital increased the maximum of the SYSGEN parameter CLISYMTBL from
500 pages to 1024 pages.  If you are use the SYMBOL040-97143 release
and increase this parameter above 500 pages, your system will crash.
This update increases the maximum symbol table size that SYMBOL will
handle to this new CLISYMTBL parameter maximum of 1024.