[[!comment format=mdwn
 username="Ilya_Shlyakhter"
 avatar="http://cdn.libravatar.org/avatar/1647044369aa7747829c38b9dcc84df0"
 subject="comment 1"
 date="2018-10-02T17:38:10Z"
 content="""
Example of where the ability to add a string to key would help:
annex.genmetadata stores year, month, and day metadata, from the file's modification date; but this will be silently overwritten if later other files with the same key but different modtime are added.  On the other hand, if I specified in .gitattributes that a random string uXXXXXX be included in the key, git-annex metadata would in effect become per-file, so one could attach metadata without worrying that it could get silently overwritten.

An heuristic alternative is to add an option to metadata --get to use the field value from the time the file was committed, rather than the current value.  But this doesn't cover the case
of two same-content files in the same commit.
"""]]
