/me do wonder if this is FHS compliant or if that dir should go under /opt ?
/service is part of the DJB daemontools hierarchy, and used strictly for runtime control. All of the entries in it should be symlinks to other directories outside of /service. It needs to be on the rootfs as well, iirc there were some bugs documented by DJB if you didn't have it there and wanted the services early in startup. There was talk about moving it to something like /var/lib/ otherwise. It can't be on /run, as it needs to persist between boots as well. I know it's still used by: qmail nullmailer bincimap qmhandle daemontools daemontools-encore relay-ctrl dev-perl/WattsUp-Daemon (also ships with a conventional init.d)