We have several conventions that we use for devices. I'll try to summarize.
Desktop names are <site code>-<service tag>: i.e. NYC-F42GXR1, BMA-FX45JFP
Server names are <site code>-<role><2 digit number>: i.e. NJE-APP01, DCO-ADC02, HCT-SQL02
Mobile devices are MOB-<type><4 digit number>: i.e. MOB-IPH0001, MOB-BBM0002, MOB-IPD0005
Network and Storage devices get more complicated due to having multiple interfaces in multiple networks, We're trying to standardize but it's a mess.... Same with telecom and a/v equipment.
We have several domains, current and legacy, but to keep it simple, there's three DNS zones. Two are AD, the other is public. No trusts.
Intranet: companycorp.com (.com was a bad idea, but not my idea)
DMZ Private: companydmz.com (.com was also a bad idea)
Public: company.com (DNS only, no AD)
We have subzones in DNS for MGMT and NET devices so as to not clog the main zones.
Intranet Network: net.companycorp.com
Intranet OOB/mgmt: oob.companycorp.com
DMZ Private Network: net.companydmz.com
DMZ Private OOB/mgmt: oob.companydmz.com
Public Network and OOB/mgmt: (none) - I wish we put in DNS but security would not allow it. If so, I'd use company.net for public (in case .com DNS was compromised, we could still reach our devices)
I hate subzones for each location. So 1995ish. Just keep it simple and have your site codes in the hostname.
As for site codes, they're all manually generated when a new office opens.
Offices are usually <1 char city><2 char state or country>: i.e. RIT (Rome), BMA (Boston, Mass.), DCO (Denver, Colo.), MRU (Moscow, Russia)
Datacenters are usually <2 char state><1 char facility>: i.e. NJE (NJ Equinix), GAQ (Georgia QTS), NYI (NY Internap)
There's some deviations but it works OK.
Amazon Cloud environment design was a nightmare, though. The default naming scheme is ip-<hex IP>. Constant debate over whether to use that and join the machines to the domains w/ those names, or to rename them instead. We ended up just deciding to issue site codes for the different AWS regions - AWV for Virginia, AWO for Oregon, AWI for Ireland, etc.
My recommendation is just device your own site codes and stop trying to wrap your infrastructure around CLLI or IATA. Those standards weren't intended for modern day scale that IT infrastructures require.
If I may ask, how large is your network, what types of devices do you host, and what is in scope for your naming schemes? Everything including the kitchen sink? Or just network devices.
Good luck! If you want to brainstorm more, PM me. I love these types of discussions and learning from others what works and what doesn't work in their environments.