The PDF format supports two types of user signatures:
- approval signatures
- certification signatures
Certification signatures in addition to signing the document also select which changes to the document shall be allowed after signing; approval signatures merely sign.
Usually the author of a document signs it using a certification signature to indicate that he is the author of the document and allows only certain additions to it (e.g. form fill-ins). A so certified document then is forwarded to other parties who (probably after form fill-ins) sign the document using an approval signature to indicate that they approve the document contents including their additions.
Your old code applied an approval signature while your new code applies a certification signature allowing “only form fill-in, signing, and page adding actions”.
Concerning your worries
My worry is because I can see that says “Certified by My company certification” and seems all ok but there is not green tick and I’m not sure if it’s completely valid.
Other than the difference described above, the certification signature is just as valid as the approval signature. As an overview of the meanings of the signature status bar icons, have a look here:
(This cheat sheet is for Adobe Acrobat and Reader 9; meanwhile the color of the certification ribbon has changed from blue to black but its meaning is still the same)
If you strictly want to go back to an approval signature, try extending the line
$pdf->setSignature($certificate, $certificate, 'tcpdfdemo', '', 2, $info);
in the example code with another parameter to
$pdf->setSignature($certificate, $certificate, 'tcpdfdemo', '', 2, $info, 'A');
which should (at first glance at the TCPDF sources) cause the code to create approval signatures.
