Because XML is a highly structured language, all documents must strictly conform
to certain rules as stated in the XML 1.0 specification. These are:
- Every document must have a single unique root element that encloses all other elements within it.
- All elements must have corresponding start and end tags. Note that XML elements are case sensitive.
- They must be cleanly nested and not overlap, e.g. <a> <b> </a> </b> is incorrect nesting.
- Attribute values must be enclosed within double quotes or apostrophes.
Shortcut:
Press the "Well Formed" button -
to perform this check.