Syntax and Namespaces

Well-formed XML requires matched tags, quoted attributes, and exactly one root element. Common parse errors come from unclosed tags, & without escaping, or mismatched nesting after copy-paste.

Namespaces

Real project files declare XML namespaces so tag names from different specs do not collide:

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
  <application android:label="@string/app_name" />
</manifest>

The xmlns:android prefix maps android:* attributes to Android's schema URI. Formatting does not change namespace semantics—it only makes structure easier to read.

Comments and declarations

• <?xml version="1.0" encoding="UTF-8"?> — optional prolog
• <!-- comment --> — may be removed or moved when reformatting; keep backups if comments matter

Key takeaway

Focus on matching tags and valid escaping first. Namespace prefixes are part of the syntax you validate before build tools run.