Steps to reproduce
Make sure there are other entities near you
Run this command:
/say @e[distance=100]
Notice only your own player name is displayed in chat
Notes
After experimenting, it appears only the sender is returned. Entities in a radius of 0 (after teleporting to it in spectator mode) aren't returned.
Linked issues
is duplicated by 14
9 more links
distance=100 is one small line at a distance of 100, use ..100 for maximum of 100.