Dear all,
           From some time now I am wondering about a way to index a set of files, lets say PDF documents. The idea is to have a unique identifier for each file and to cross-reference using this identifier. For instance, I use a project management (PM) software (web based) on a public server of my university. Then I have a set of tasks saying, review document X, or Y. And those documents are stored on an internal server of my lab.
I see several options:

1. Upload the required documents to the PM site and directly link
2. Share online my internal server and use the URL of the docs in the PM
3. Just use the unique identifier in the PM, and then look in git annex for that ID
4. Use some sort of document management system (DMS)

Options 1 and 2 are impractical for several reasons. Option 4 usually requires that your files are inside the DMS.
So my questions are: 

* Do you think this is doable with git-annex?
* Is there an easy way to ask it: give me the document with this index?
* I think the best answer for this question is: git annex find --include '*' --format='${key} ${file}' | grep <KEY>
* And conversely, how do I find the key of a certain document?

Thanks in advance.
Best,
       Juan
