I have discoverd that these appear to be ships\targets that are targetable\visible in your contacts panel but at longer range than weapons etc.
If you target from context panel - they lock on with a different icon, with the arrow indicating some kinda "direction" to your target. Its wierd, intermittant so maybe wrong.. but repeated with a wingmate a few times, other NPCs like cruisehips and such also show up if targetted and not in your immediate view.
Like a "3D" icon pointing to the contacts panel "contacts". I will attach some images below to try and demonstrate what i mean, here you see the icon and just happens to be close and directly in front view, so you can also see the larger diamond icon indicating a lockaable ship. I can then lock - and see its a NPC ship.
If this 'new' icon was something the side or behind my ship, it would have the arrow indicator - and depending on whether its something you can target, or distance the icons do change in colour and style (full circle if locked). These are the "variants" also called out by Sighman and in his
post # 11 in this thread (6 above)
Here how it appears without clicking on it, from my Contacts panel it indicated a a list of contacts including a Type 7 ship.
The "selecting" it in contacts, it locked it in my front view .. and icon changed - and indicated same Type 7.