#28933
PDF form elements appear in PDF like that:
[language=css:2g057b72]2 0 obj
<<
/Type /Annot
/Subtype /Widget
/Rect [125 939 38 929]
/T (i1)
/AP <>
/FT /Tx
/Ff 0
/F 4
/MK <<
/BG [1 1 1]
>>
/Subtype /Widget
/DR <>
/V (val1)
/DV (val1)
>>[/language:2g057b72]
/Rect [125 939 38 929] is a bounding box of the form element there.
