Hi,
I am relatively new to this community but I had several looks into the BIDS specification and this forum and haven’t found any information related to my questions below - maybe you can elucidate me 
I wondered whether it would be possible to come up with a tag for what is actually seen in the MRI volumes.
If one thinks about spinal cord imaging many of the specifications would not change but it would be critical to specify that it is not a brain what is measured here 
In these terms I wondered whether people have already incorporated somewhere whether a whole brain is covered or whether it only contains a partial field of view. I thought this might as well be of relevance for some pipeline like FMRIPREP but I haven’t found any information on that.
In some way the BIDS standard of course assumes that there is always a (whole?) brain underlying that neuroimaging data but as the format extends more and more it might of interest? I already looked at the github page for contributing to the BIDS specification but wanted to ask first what you think about it and if you could give me more information on these questions (maybe I missed something).
Thank you in advance!
Ulrike