explain nrsign & lsign?

[snowcrash+gnupg-users]

> There is somewhat constant debate over the best method. ...

> the main point of signing a key is so that GnuPG (or PGP) can
> use the signature in its trust calculations ...

good info. thanks.

last (yeah, sure ...) question, then.

does gpg, &/or do the keyservers, require *valid* email addresses for keys?

i.e., if my "A" trust-signing key will *never* be used to sign an
email, can its assigned/defined address be, e.g.,

   trust_sig at mydomain.local

?

will *it*, and sigs/keys for 'real' addresses signed *by* it, be
retrievable as such from the keyservers manually and via 'automatic'
Key Retrieval options?

thanks!