Transcription: So in concept, the only real difference here between internal entities that we've seen before and parameter entities, which you're just seeing now, is one, the markup character, the percent sign, and two, where you can use them. The scope of a parameter entity is within the document type definition. The scope for an internal entity, after it's declared in the document type definition, is within the content of the XML document. But there are some very specific rules about parameter entities that you may find interesting.
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