NFC: why won't file open when linked to an application?

[farfields]

I'm using NFC tags, and want to put a file URI on a tag associated with an application to open it.

In principle, this ought to be straight forward:
copy a file link to the tag writer application (I'm using the NXP tagwriter). This is type file: ///mnt/sdcard/.... where the file location is copied in, e.g. a pdf
Select AAR with a suitable application, e.g. Adobe Reader.

When I tap the tag to read it, the tag is read ok. The Adobe Reader application opens, but the selected file is not read in.

I've repeated this using Open Office, Office Suite, Quick Office. None will open the associated file, they just open the application.

This is supposed to be a standard function of NFC isn't it?

Any advice to fix this?

The purpose is to program tags with links to specific files, so that when tapped each file will open ready to viewed by the user.

Cheers.