[db-wg] Prefix length for the "pingable" attribute

Hi WG,

The documentation unequivocally states the value of the "pingable"
attribute in route[6] objects must include a prefix length:

$ whois -h whois.ripe.net -- -v route
[...]
pingable

   Allows a network operator to advertise an IP address of a node that
   should be reachable from outside networks. This node can be used as a
   destination address for diagnostic tests. The IP address must be
   within the address range of the prefix containing this attribute.

     An address prefix is represented as an IPv4 address followed
     by the character slash "/" followed by an integer in the
     range from 0 to 32.  The following are valid address
     prefixes: 128.9.128.5/32, 128.9.0.0/16, 0.0.0.0/0; and the
     following address prefixes are invalid: 0/0, 128.9/16 since
     0 or 128.9 are not strings containing four integers.

$ whois -h whois.ripe.net -- -v route6
[...]
pingable

   Allows a network operator to advertise an IP address of a node that
   should be reachable from outside networks. This node can be used as a
   destination address for diagnostic tests. The IP address must be
   within the address range of the prefix containing this attribute.

     <ipv6-address>/<prefix>

Therefore I added mine as /32 and /128. That ended up in me getting
complaints that I broke some people's scripts, which were assuming that
value of this attribute should be a "bare" IP address. (For example:
http://ip.v6net.ru/archives/1764)

Contradictory to what the documentation says, the e-mail robot happily
accepted my update to remove the prefix length. So hopefully people's
scripts are unbroken now. This sparked my curiosity, though:

- What exactly is the purpose of the prefix length?
- How should one interpret a value that has a prefix length other than
/32 (in "route" objects) or /128 (in "route6" objects)?
- Why does the documentation say it is mandatory when it clearly is not?
- And finally, am I really the only LIR hostmaster in the RIPE that
actually do RTFM? :-)

$ curl -s ftp://ftp.ripe.net/ripe/dbase/split/ripe.db.route{,6}.gz | zgrep -c '^pingable:.*/'
0

Tore