Original text:
true, indicates the client's agreement with the terms of service. This field cannot be updated by the client.  A URL from which a list of orders submitted by this account can be fetched via a POST-as-GET request, as described in orders-list. allows a client to look up an account URL based on an account key (see finding-an-account-url-given-a-key). <del> An optional field for binding the new account with an existing non-ACME account (see external-account-binding ). </del>  The server MUST ignore any values provided in the "orders" fields in <del> account bodies sent by the client, as well as any other fields that </del>  it does not recognize.  If new fields are specified in the future, the specification of those fields MUST describe whether they can be <del> provided by the client. In general, the server MUST ignore any fields in the request object that it does not recognize.  In particular, it MUST NOT reflect unrecognized fields in the resulting account object.  This allows clients to detect when servers do not support an extension field. </del>  The server SHOULD validate that the contact URLs in the "contact" field are valid and supported by the server.  If the server validates Initial contents: The fields and descriptions defined in account- objects.  9.7.2. The "ACME Order Object Fields" registry lists field names that are

Reviewer comments:
From Section 7.3: "MUST URL account bodies sent by the URL other fields that it does not recognize" in the first paragraph seems to be unnecessarily repeated by "MUST ignore any fields in the request object that it does not recognize" in the second paragraph. This PR merges these two paragraphs and discards the duplicated text. Also, "account bodies" isn't used anywhere else in the document, so this PR changes it to "account objects".
This looks reasonable to handle in AUTH48.
the last part isn't purely editorial, but okay.

Revised text:
true, indicates the client's agreement with the terms of service. This field cannot be updated by the client. <ins> Including this field in a newAccount request indicates approval by the holder of an existing non-ACME account to bind that account to this ACME account.  This field is not updateable by the client. (See external-account-binding). </ins> A URL from which a list of orders submitted by this account can be fetched via a POST-as-GET request, as described in orders-list. allows a client to look up an account URL based on an account key (see finding-an-account-url-given-a-key).  <ins> Same meaning as the corresponding server field defined in </ins> The server MUST ignore any values provided in the "orders" fields in  <ins> account objects sent by the client, as well as any other fields that </ins> it does not recognize.  If new fields are specified in the future, the specification of those fields MUST describe whether they can be  <ins> provided by the client.  The server MUST NOT reflect the "onlyReturnExisting" field or any unrecognized fields in the resulting account object.  This allows clients to detect when servers do not support an extension field. </ins> The server SHOULD validate that the contact URLs in the "contact" field are valid and supported by the server.  If the server validates Initial contents: The fields and descriptions defined in account- objects. <ins> | Field Name | Field Type | Requests | Reference | |:-----------------|:-----------|:---------|:-------| ======= | status | string | new, account | RFC 8555 | | contact | array of string | new, account | RFC 8555 | | externalAccountBinding | object | new | RFC 8555 | | termsOfServiceAgreed | boolean | new | RFC 8555 | | onlyReturnExisting | boolean | new | RFC 8555 | | orders | string | none | RFC 8555 | </ins> 9.7.2. The "ACME Order Object Fields" registry lists field names that are