I want to develop a "Custom Action" for all of document libraries in a site collection, I tried looking on Google but couldn't find any relevent tutorial.
Custom action has to be in "Actions" and below "Export to spreadsheet".
Edit
I got custom Document libraries as well as out of box ones and since I don't want to relate this action to lists I will have to find out what can I use for "RegistrationType", "RegistrationID" and "Location"
For a normal list its something like this,
Location="EditControlBlock"
RegistrationId="11000"
RegistrationType="List"
but not sure what would be location for this "actions" and whether I can do something to relate it to all document libraries out of box or custom ones
Edit 2
I find what I was looking for here
http://blog-sharepoint.blogspot.co.uk/2011/11/sharepoint-2010-extend-document-library.html
however still not sure if it will work for custom document libraries or not.