mention reverse dns

tsa/howto/retire-a-host.mdwn

@@ -5,7 +5,7 @@
  3. if applicable, undefine it: `virsh undefine $host`
  4. if applicable, remove the LVM logical volumes or virtual disk files
  5. remove it from ud-ldap: the host entry and any `@<host>` group memberships there might be as well as any sudo passwords users might have configured for that host
- 6. if it has any associated records in `tor-dns/domains` or `auto-dns`, remove it from there too
+ 6. if it has any associated records in tor-dns/domains or auto-dns, or upstream's reverse dns thing, remove it from there too
  7. on pauli: `read host ; puppet node clean $host.torproject.org && puppet node deactivate $host.torproject.org`
  8. grep the `tor-puppet` repo for the host (and maybe its IP addresses) and clean up
  9. clean host from `tor-passwords`