According to the PDF Specification:
The definition of an indirect object in a PDF file consists of its object number and generation number, followed by the value of the object bracketed between the keywords obj and endobj. For example, the definition:12 0 obj
( Brillig )
endobj
An invalid case:
2545 0 obj
<<
/Type /Page
/Parent 2537 0 R
/Contents 8 0 R
/Resources 2538 0 R
>>
2546 0 obj
....