port 

<p>The port element describes an anchor point to which arcs can refer as a source or target. It consists of:
  <ul>
    <li>absolute 2D cartesian coordinates (PointAttribute),</li>
    <li>a unique id attribute.</li>
  </ul>
</p>
<p>Two port elements are required for process nodes. They represent the extremity of the two "arms" which protrude on both sides of the core of the glyph (= square or circle shape). Other glyphs don't need ports (but can use them if desired).</p>

Element Information

Model

notes{0,1} , extension{0,1}
Children: extension, notes

Attributes

QName Type Fixed Default Use Inheritable Annotation
id xsd:ID required 
<p>The xsd:ID type is an alphanumeric identifier, starting with a letter. Port IDs often contain the ID of their glyph, followed by a local port number (e.g. glyph4.1, glyph4.2, etc.) However, this style convention is not mandatory, and IDs should never be interpreted as carrying any meaning.</p>
x xsd:float required
y xsd:float required

Used By

Elements arc, glyph

Source 

<xsd:element name="port">
  <xsd:annotation>
    <xsd:documentation>
      <p>The port element describes an anchor point to which arcs can refer as a source or target. It consists of:
        <ul>
          <li>absolute 2D cartesian coordinates (PointAttribute),</li>
          <li>a unique id attribute.</li>
        </ul>
      </p>
      <p>Two port elements are required for process nodes. They represent the extremity of the two "arms" which protrude on both sides of the core of the glyph (= square or circle shape). Other glyphs don't need ports (but can use them if desired).</p>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:complexType>
    <xsd:complexContent>
      <xsd:extension base="SBGNBase">
        <xsd:attributeGroup ref="sbgn:PointAttributes"/>
        <xsd:attribute name="id" type="xsd:ID" use="required">
          <xsd:annotation>
            <xsd:documentation>
              <p>The xsd:ID type is an alphanumeric identifier, starting with a letter. Port IDs often contain the ID of their glyph, followed by a local port number (e.g. glyph4.1, glyph4.2, etc.) However, this style convention is not mandatory, and IDs should never be interpreted as carrying any meaning.</p>
            </xsd:documentation>
          </xsd:annotation>
        </xsd:attribute>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>
</xsd:element>

Sample