What's "caffe.proto" used for?

[Jon]

What's the caffe.proto file used for? If I want to add a new layer type, how should I change this file?

[Dinesh]

The enum in caffe.proto that required you to list your layer name has been removed from the latest revisions of Caffe. Now, caffe.proto only ever has to be edited if you need to define new parameters for your layer. See https://github.com/BVLC/caffe/wiki/Development