.">Code::S_END_SENTINEL</a>. If, when adding a new revision of the code, you deprecate a value in this <code>enum</code>, do not delete it from this <code>enum</code>. Instead mark it as deprecated here and then remove it from Ipc_transport_category::message().</p>
<p >Errors that indicate apparent logic bugs (in other words, assertions that we were too afraid to write as actual <code>assert()</code>s) should be prefixed with <code>S_INTERNAL_ERROR_</code>, and their messages should also indicate "Internal 