ip route get recognizes address as anycast

# ip route get 1.2.3.4
anycast 1.2.3.4 dev eth0  src 5.6.7.8

and the question is how does it know the address is an anycast ? (which apparently is true).

UPDATED:

Present as anycast route:

root@hv2 ~ # ip route get 1.2.3.4
anycast 1.2.3.4 dev eth0  src 5.6.7.8 
    cache 

but not visible in list:

root@hv2 ~ # ip route list|grep 1.2.3.4|wc -l
0

but it's possible to delete it, and than it back to normal (no anycast anymore):

root@hv2 ~ # ip route del anycast 1.2.3.4 dev eth0
root@hv2 ~ # ip route get 1.2.3.4
1.2.3.4 via 5.6.7.8 dev eth0  src 9.10.11.12 
    cache