💡 When in doubt...
It's pretty straightforward: most of the time, just use your own callsign.
Because you have a U.S. license and are operating stations within the U.S., you do not need any further identification beyond your regular callsign.
🌎 What about my location?
It doesn't matter where you are sitting – what really matters is where the RF is being emitted.
When sharing your location with other operators, you should explicitly use the location of the station you are operating. Every station has its county, state, CQ region, ITU region, and grid square listed at the top.
For example, if you are exchanging grid squares during a VHF contest, send the grid square of the station you are connected to, not the grid square of where you, the operator, are physically located.
You may choose to add a prefix or suffix to your callsign to identify the geographic region of the station you are remotely operating, but it is not required.
🚫 What NOT to do
Never identify yourself using a non-U.S. callsign.
Never identify yourself using someone else's callsign.
Never claim to be operating from your home location instead of the remote station's location.
⚠️ Exceptions to the rule
KP4/Palmas
This station is located in Puerto Rico, a U.S. Territory. You should identify using your callsign with a KP4 prefix. For example, KP4/WW1X.
9A/Croatia
This station is located in Croatia and participates in CEPT. You should identify using your callsign with a 9A prefix. For example, 9A/WW1X.
HH2/Haiti
This station is located in Haiti, which does not participate in CEPT. This is a special station that always operates under the callsign HH2AA.