What is generating this data?

• The first has a single HTML tag, with no closing tag, while the second has opening and closing tags.
• This first has a non-standard tag, while the second has valid HTML tags.
• The second has the chunk enclosed in angle brackets. is that what makes it acceptable?
• Does it matter that your tags are only acceptable HTML 4? XHTML requires lower case tags.
• Since HTML documents are not line-oriented, breaks can occur anywhere, or many components can be one one line. Is that relevant to your document?