I use DOpus to label documents. Those documents are synced to my Dropbox account in the cloud. If I leave the synced copies in the cloud as an archive and delete the copies on my C: drive will the label info remain on the files stored in the cloud so I can retrieve the archive copies years down the road and find them based on their labels?
Labels can be stored either of two places/ways:
-
NTDS ADS metadata (the default): The labels are stored in the filesystem, joined to the file but in a separate data stream.
Dropbox probably does *not * preserve this extra data, so the labels would most likely be lost if the local copy was deleted.
This metadata can also be lost when some software edits or overwrites the file, if it doesn't do so in a way which preserve NTFS ADS. Similarly with copies made by software which doesn't preserve the data (which can include Opus if it isn't configured to), or when copying to things like FAT32 USB sticks and most archive formats which don't support NTFS ADS at all.
-
In the configuration (not the default): The labels are stored in your Opus config, not in the filesystem, and each label is tied to a particular path, not to any actual file.
When stored that way, the labels will survive the file being deleted and later recreated, as long as you're still using the same Opus configuration (and haven't cleared out the old labels). Edits and overwrites by other programs will not affect the labels stored that way. But the labels won't follow the file if it is copied, moved or renamed.
Thank you very much for your reply. Since I am a DOpus newbie and I do not consider myself a power user I am concerned I will spend time and effort labeling files that may not retain that information because I make a mistake somehow. As an alternative I studied the Reference Manual to learn how to edit metadata and add a tags to my pdf documents. Will my pdf documents retain the tags in meta data despite where they may be stored or whether or not they are copies.
It depends which metadata you mean. If the PDF format supports it, and Opus knows how to write it into the PDF file itself, then the data will be stored inside the PDF file and should be preserved (unless something goes out of its way to clear it).
For example, PDF files support an Author field which works that way.
But some metadata cannot be saved into the PDF format, and will always be written to NTFS ADS (e.g. the PDF format does not, as far as we know, define a way to store the Rating column where you can rate a file out of 5 stars).
The best thing to do is try it and see.
Thank you
And star rating of MP3 and FLAC Files are also stored inside the files and not in ADS. It's well done, because media playback software can read the rating, too. Only Windows File Explorer can only read MP3 rating and not FLAC rating. 
That is completely over my head 
Time will tell. 