The NIS alias map needs to contain a @:@ entry to indicate that it is fully updated and ready for reading. But because HP-UX omits the @:@, it is useful only as a check to see whether the NIS map exists. The -d38.10 debugging switch causes the result of this check to be printed as:

nis_map_open: yp_match(@, domain, nisdb) 

Here, domain is the NIS domain, and nisdb is usually mail.aliases (but it can be redefined in your configuration file, AliasFile). If the database map is not marked as optional (-o), the following error will be printed:

Cannot bind to map nisdb in domain domain:  reason  here 

The -d38.10 debugging switch also traces the NIS+ open's check for a valid table:

nisplus_map_open: nisplusdb.domain is not a table

Essentially, this says that the NIS+ database map nisplusdb (in the domain shown) does not exist. The error is printed even if the -o (optional) database switch (-o) is present.