I'm using rsync to back up folders from my iMac to a WD MyBook and the process seems to leave files such as these:
_0O1MN~H.MP4 _2C0X2~3.AVI _ALLYW~B.SRT _VUC69~7
The last one is the most common, finding one in each folder at times. The others (shadows of other files judging by the extensions) not so common but when I find them there are multiples in the same folder. A one off so to speak.
I read somewhere some time back, but can't find it, that it may actually have something to do with the mode I am accessing the MyBook with. eg. SMB rather than .. and here's where my recall fails me.
EDIT: ok I've found the other means of access, particular to OSX it seems:
AFP - Apple Filing Protocol
EDIT: they also seem to defy deletion, in some cases. but on discovering the AFP access I think that might be the access that allows me to delete them (with less messing around).
ok, I couldn't find at first because I had been deleting them,manually so I was in the process of doing another rsync to see if I could reproduce; I noticed in the file build list (for a dry run) that I had one on the local HDD!
"Get info" tells me it's a "Unix Executable". The file was in a hidden ".AppleDouble" folder. When I put that to the "file <>" test you asked for it told me:
_VUC69~7: AppleDouble encoded Macintosh file.
(ps. am I able to do linefeeds in comments as I'm struggling to do it O_o)