[Tagging] foot=yes or bicycle=yes on track without other limitations?

[Maarten Deen]

Is there a deeper meaning of adding foot=yes or bicycle=yes to 
highway=track or highway=path without adding other limitations? I 
thought track and path are by default routable for foot and bicycle, so 
IMHO they add nothing.

Examples:
http://www.openstreetmap.org/browse/way/53561813
http://www.openstreetmap.org/browse/way/68796031
http://www.openstreetmap.org/browse/way/195440134

Regards,
Maarten