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X3D spec sayeth</div>
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<div class="elementToProof">X3D 4.0 Architecture, 7 Core component, 7.2.5.1 Organization</div>
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<div class="elementToProof">(last paragraph) "Comments may appear at various places throughout an X3D model, with syntax varying according to file encoding. Comments have no effect on scene functionality. Comments are not X3D nodes and not X3D statements. Comments
may be interspersed between other X3D nodes and statements as long as they do not interfere with the functionality of the model."</div>
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<div style="margin: 0px;">https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/core.html#Organization</div>
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<div class="elementToProof">Table 7.2 — Core component support levels</div>
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<div class="elementToProof">https://www.web3d.org/specifications/X3Dv4/ISO-IEC19775-1v4-IS/Part01/components/core.html#t-CoresupportLevels</div>
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<table summary="Support levels" style="text-align: center; margin-right: auto; margin-bottom: 18px; margin-left: auto; width: 932.448px; box-sizing: border-box; border-collapse: collapse; border-spacing: 0px;">
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<div style="text-align: center;"><b>Level</b></div>
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<div style="text-align: center;"><b>Prerequisites</b></div>
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<div style="text-align: center;"><b>Nodes/Features</b></div>
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<div style="text-align: center;"><b>Support</b></div>
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<div style="text-align: left;"><b>1</b></div>
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<div style="text-align: left;">None</div>
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<div style="text-align: left;">Comments</div>
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<div style="text-align: left;">Full Support</div>
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Here are corresponding sections from draft XML and ClassicVRML encoding specifications. Review and comment are welcome.</div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 255);">19776-1 XML Encoding version 4.0, 4. Concepts, 4.3.4
<b>Comments</b></span></div>
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<div><span style="background-color: rgb(255, 255, 0);">Comments do not affect the rendering or interaction of an X3D model. Nevertheless, comments are essential information to communicate author intent, design considerations, model capabilities, and expectations
for continued development. Comment functionality is described in ISO/IEC 19775-1 X3D Architecture, Core component, 7.2.5.1 Organization.</span></div>
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</span></div>
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<div><span style="background-color: rgb(255, 255, 0);">A single form for comment syntax is possible in the X3D XML encoding, exactly matching that defined by XML.</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"><br>
</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);">EXAMPLE</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> <WorldInfo/> <!-- this is a comment between elements (nodes or statements) --></span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> </span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> <!-- this is another XML comment</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> <WorldInfo/></span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> <Group/></span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> --></span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);"><br>
</span></div>
</div>
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<div><span style="background-color: rgb(255, 255, 0);">XML comments are not allowed within XML elements (i.e. X3D nodes or X3D statements). Whitespace within XML comments may be normalized.</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"><br>
</span></div>
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<div><span style="background-color: rgb(255, 255, 0);">It is important to consider that X3D model comments might not necessarily be preserved by intermediate processes when compressed, or when X3D files are relayed over the Web. Further, the exact placement
of comments within an X3D model's structure may necessarily vary among X3D file encodings and programming language bindings. When appropriate, critical model information can also be retained in a lossless and consistently structured fashion by capturing it
within META statements or the various Metadata nodes.</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 255);">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-1v4.0-WD1/Part01/concepts.html#Comments</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 255);">Tracked in Mantis 1487: syntax for XML comments</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 255);">https://mantis.web3d.org/view.php?id=1487</span></div>
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and</div>
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<div class="elementToProof">19776-2, X3D Classic VRML Encoding v4.0 draft, 4 Concepts, 4.3.4
<b>Comments</b></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);">Comments do not affect the rendering or interaction of an X3D model. Nevertheless, comments are essential information to communicate author intent, design considerations, model capabilities,
and expectations for continued development. Comment functionality is described in ISO/IEC 19775-1 X3D Architecture, Core component, 7.2.5.1 Organization.</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);">Two forms of comment syntax are possible in the Classic VRML encoding, single-line comments and block comments, each described in Grammar A.1.2 Overview.</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);"><br>
</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);">EXAMPLE</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> WorldInfo { } # this is a single-line comment between nodes and statements</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> </span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> WorldInfo {</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> title "comment test" # this is another single-line comment following a field</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> }</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> </span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> #/* This is a block comment</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> WorldInfo { }</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> Group { }</span></div>
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<div><span style="background-color: rgb(255, 255, 0);"> */#</span></div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);"><br>
</span></div>
</div>
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<div class="elementToProof"><span style="background-color: rgb(255, 255, 0);">It is important to consider that X3D model comments might not necessarily be preserved by intermediate processes when compressed, or when X3D files are relayed over the Web. Further,
the exact placement of comments within an X3D model's structure may necessarily vary among X3D file encodings and programming language bindings. Critical model information can also be retained in a lossless and consistently structured fashion by capturing
it within META statements or the various Metadata nodes.</span></div>
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<div class="elementToProof">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-2v4.0-WD1/Part02/concepts.html#Comments</div>
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<div class="elementToProof"><br>
</div>
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<div class="elementToProof">Annex A Grammar, A.1.2 Overview</div>
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<div class="elementToProof">For the Classic VRML encoding, the # character begins a comment. The first line of the file, the header, also starts with a # character. Two forms of comment are allowed, a single line comment and a block comment. A single line comment
starts with a # and continues until the next line or file terminator, whichever comes first. A block comment starts with #/* and continues until */#. Line terminators are ignored. An unterminated block comment is an error.</div>
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<div>Within either a single line comment or a block comment, all characters are ignored except as described above. A single line or block comment cannot start within a double-quoted SFString or within MFString fields. Within an SFString or MFString field, the
# character or #/* character sequence is considered part of the SFString or MFString field.</div>
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<div class="elementToProof">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19776-2v4.0-WD1/Part02/grammar.html#Overview</div>
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<div class="elementToProof">Tracked in Mantis 1486, syntax for Classic VRML comments</div>
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<div class="elementToProof">https://mantis.web3d.org/view.php?id=1487</div>
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Hopefully this adds clarity in a sometimes-tricky topic. Parsing is always an exceedingly strict business, so careful checking is welcome.</div>
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<br>
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Personal motto: comments and skateboarding are not a crime.</div>
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<br>
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# Have fun with X3D! 🙂</div>
<div id="Signature" class="elementToProof">
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;"><br>
</span></p>
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;">all the best, Don</span></p>
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;">--</span></p>
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;">Don Brutzman Naval Postgraduate School, Code USW/Br brutzman@nps.edu</span></p>
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;">Watkins 270, MOVES Institute, Monterey CA 93943-5000 USA +1.831.656.2149</span></p>
<p style="margin: 0in; font-family: Calibri, sans-serif; font-size: 11pt;"><span style="font-family: "Courier New"; font-size: 9pt;">X3D graphics, virtual worlds, navy robotics https://faculty.nps.edu/brutzman</span></p>
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