diff --git a/compatibility.bs b/compatibility.bs
index 3bda92d..86f5b11 100644
--- a/compatibility.bs
+++ b/compatibility.bs
@@ -89,6 +89,8 @@ specified elsewhere.
The HTTP User-Agent
header field as found in major browsers today is also described.
+The removals of some features from the web platform are also described.
+
All diagrams, examples, and notes in this specification are
non-normative, as are all sections explicitly marked non-normative.
@@ -1055,11 +1057,102 @@ On mobile platforms, including smaller iPad form factors
+
+Deprecation and Removal
+
+While the web platform stives for backwards-compatibility, there are occasions which require the
+outright removal or discouraged use of some features. To support making these changes
+in the least disruptive and most consistent way for developers, we document them here. This is most
+beneficial as a decalration of intent by browser engines to act together in a well reasoned way.
+
+Feature List
+
+
+
+
+ Feature |
+ Deprecation |
+ Removal |
+ More Information |
+
+
+
+
+
+
+
+
+Process
+
+Anyone may suggest an addition to the list by filing an issue on this specification. Each added row
+that includes [=deprecated feature list/Removal|removal information=] should correspond to a normative
+change in the specification that defined this behavior before its removal.
+
+Note: For sake of the WHATWG Working Mode, adding
+a row to this table is a removal.
+
+Note: [[#removal-criteria]] provides suggested criteria to consider when deciding if it is appropriate
+to remove the feature to the web.
+
+Each entry should include:
+
+
+ - the [=deprecated feature list/Feature|feature or behavior=] that is being removed or deprecated.
+
- what browser engines have [=deprecated feature list/Deprecation|deprecated=] the feature or behavior, discouraging its further use.
+
- when the feature will be, or has been, [=deprecated feature list/Removal|removed=] from browser engines, preventing its use by default. This may be empty if there is no such plan.
+
- a link to non-normative [=deprecated feature list/More Information|more information=] about the removal, such as justification for the removal, alternatives to use, or automated tools to improve developer experience.
+
+
+Criteria for removal or deprecation
+
+This section is non-normative.
+
+The bar to make a breaking change in the web platform across multiple browser engines can be high.
+This is a good thing, as the web should strive for backward compatibility as much as is possible.
+The WHATWG Working Mode even establishes
+further requirements for changes to specifications that remove behavior. This section provides an
+incomplete enumeration of criteria that should be considered before including a feature in the
+[[Feature List]]. This is not an algorithm to decide what can be removed; each feature removal is
+unique and requires the careful decision making of the implementers to weigh the costs and benefits
+of proceeding with removal.
+
+Harms of removing the feature are good reasons to not proceed:
+
+
+ - User-visible breakage of any site is a harm worth considering
+
- The full set of use-cases for a feature can not be known, so unexpected things may break
+
- Removal of features has an outsized influence on smaller development operations that have fewer resources for maintanance and can not track the changes to the web platform closely
+
- Removal of features can disrupt ecosystems built on the web, changing their economics and incentives, and this is not always for the better
+
+
+Benefits of removing the feature are good reasons to proceed:
+
+
+ - Security improvement
+
- Privacy and user protections improvement
+
- Accessibility improvement
+
- Platform architectural improvement
+
+
+Harms of removing the feature may be mitigated by some choices:
+
+
+ - Lead time from deprecation to removal
+
- On-by-default, but easily disabled for a site by developers during the deprecation
+
- Coherence of action by browsers
+
- Mechanisms for site-specific workarounds controlled by the browser
+
- Strong, interoperable alternatives to the feature
+
- Younger and less-stable APIs are less ossified and are likely used by developers more apt to fix their website
+
+
+It is important to note that any alternatives to the feature will face the same scrutiny when they are to be removed,
+deferring the issue of breakage rather than resolving it.
+
Acknowledgements
-Thanks to Alan Cutter, Cameron McCormack, Chris Rebert, Chun-Min (Jeremy) Chen, Daniel Holbert,
-David Håsäther, Domenic Denicola, Eric Portis, hexalys, Jean-Yves Perrier, Jacob Rossi, Karl Dubost,
-Philip Jägenstedt, Rick Byers, Simon Pieters, Stanley Stuart, William Chen and Your Name Here for
-feedback and contributions to this standard.
+Thanks to Alan Cutter, Benjamin VanderSloot, Cameron McCormack, Chris Rebert, Chun-Min (Jeremy) Chen,
+Daniel Holbert, David Håsäther, Domenic Denicola, Eric Portis, hexalys, Jean-Yves Perrier, Jacob Rossi,
+Karl Dubost, Philip Jägenstedt, Rick Byers, Simon Pieters, Stanley Stuart, William Chen and
+Your Name Here for feedback and contributions to this standard.
Thanks to Mounir Lamouri and Marcos Cáceres for defining the {{ScreenOrientation}} interface.
[[!screen-orientation]]