[RFC] Defining semantics for "implied directories" in the image spec #1170

opencontainers/image-spec#970 represents an attempt to codify the semantics for "implied directories" (directories which must exist to apply a layer, but that do not have their own tar entries), particularly as it relates to filesystem attributes.

As this affects how high-level runtimes interpret images and is fairly low-level, input and awareness from runtime authors is requested. Thanks!