[Imports] "readonly" tag for imported data (ask "simple" editors to not modify)?

[Jan Iven]

I find myself occasionally adding nodes to data that I assume will be
updated regularly from "authoritative" sources - examples such as

* YAHOO image cover (high-res or other)
* natural reserve boundaries
* administrative boundaries e.g from the french cadastre
* EU CORINE land cover

Most of them span large areas/length, are coarse resolution and tend to
roughly follow natural features. And often there is a way/path close to
the edge.. I'd like to add such ways with higher resolution, but editors
are trying to snap to the existing feature (a bit of a hassle). I assume
that these datasets get occasionally scrapped and re-imported, so there
is no point in improving accuracy for them.

As such, is there some agreed way for a large-scale import to pass the
message to editors such as Potlatch that they need not bother editing
these features? (this would allow me to go off and pester these editors
to actually honour such an attribute). Of course, the editor could chose
not to honour this (i.e. JOSM when importing/improving some CORINE
areas), but at least this would then be intentional.

Thanks in advance for any pointers
jan

PS: If on the other hand I knew that CORINE is taking back OSM data, I'd
be happy to edit/refine these areas - the "land cover" provides a nice
background for cycle maps. So an alternative tag could be saying
"auto-import data, but your edits will be taking into account upstream"