The list could get long and complicated.

A blank piece of white washing liquid bottle rolls up nicely with the blob
and anything can be quickly written on it with a small pencil attached by
string (or even a strip of gaffer tape).

A blank slate would need treating as per group plans for yellow blob.

The yellow blob plan with UKRS group dives changed a little over time.
Initially the yellow could be carried as reserve and used without raising
alarm if the primary was lost. The warning sign was when it appeared on the
same line as an orange blob.

Posts started referring to any sight of the yellow as an alert, making it
necessary to carry THREE buoys and reels including the backup orange.

-"DON'T PANIC Lost Primary..Doh!"
could be added to the list ;o)

Have any agencies adopted the yellow buoy system and written some kind of
standard or guidance on this system?

Rob H