Merge pull request #397 from IHE/JohnMoehrke-patch-1

Update ch-E.html

GeneralIntro/ch-E.html

@@ -69,8 +69,11 @@ <h3 id="E.1.1">E.1.1 Normative versus informative contents of the Technical Fram
 non-normative.
 </p><p>
 IHE adopts the normative words defined in IETF <a href="https://www.rfc-editor.org/info/bcp14">Best Current Practice 14: Key words for use in RFCs to Indicate Requirement Levels (BCP-14)</a> (currently RFC <a href="https://www.rfc-editor.org/info/rfc2119">2119</a> and RFC <a href="https://www.rfc-editor.org/info/rfc8174">8174</a>), certain words indicate whether a specific content of the Technical
-Framework is normative: either required (e.g., “must”, “required”, “shall”) or optional (e.g.,
-“may”, “recommended”). Informative content does not contain these key words.
+Framework is normative. 
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
+"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
+document are to be interpreted as described in <a href="https://www.rfc-editor.org/info/rfc2119">RFC 2119</a>.
+Informative content does not contain these key words.
 	  </p>
       <h2 id="E.2">E.2 Profiling DICOM</h2>
       <p>The required behaviors for DICOM Type 2 attributes are sometimes misunderstood by implementers. IHE emphasizes that DICOM Type 2 attributes (for instance, Patient Name, Patient ID) shall be transmitted with zero length if the source system does not possess valid values for such attributes; in other words, the source system shall not assign default values to such attributes. The receiving system must be able to handle zero-length values for such attributes.</p>