Sending this to the mailing list as a heads-up since it relates to the License Inclusion Principles [1].
Following from recent SPDX legal team calls, we realized that the License Inclusion Principles speak only to what goes on the SPDX License List [2], but not what goes on the SPDX Exceptions List [3]. The guiding principle the team has used for what goes on the Exceptions List has been the language at the top of that page: "These exceptions grant an exception to a license condition or additional permissions beyond those granted in a license; they are not stand-alone licenses."
As discussed on a recent call, I've submitted a PR [4] intended to capture this concept as part of the License Inclusion Principles document, using structure and language similar to what's in that document already for licenses.
Note that this is _not_ meant to say anything about the pending Change Proposal [5] for custom exceptions / modifiers / additions / whatever, which has been previously discussed here and which I'd encourage people who are interested to go and weigh in on separately. This is also _not_ intended to reflect any change in policy or approach, rather to explicitly codify how we've been doing things up till now.
Please feel free to take a look and weigh in. We will likely plan to merge this PR tomorrow during the standard legal team call, though can always iterate on it later if desired.