Eurovelo 4 in Nederland.
EV4 is routed on the road over the national route LF13. AFAIK EV4 is not signposted as such, cyclists are supposed to follow LF13.

In OSM EV4 part NL has its own icn relation, serving as a section in the superroute relation.

Why not use the LF13 relation as a section of the EV4 relation? I guess the cross-border ways are not part of LF13, so EV4 would have gaps.

Some would say, the EV4 is not signposted in NL so it should not be mapped at all. Others would say, the signs are not explicitly EV4, but there is signage which counts as eurovelo, so it’s ok to map it. I tend to agree with “others”, but I think the change to following LF13 shields should be tagged somewhere in the EV4-NL section relation. That is information that the cyclists need when planning and executing their trip.