Hans, I have the following sample: \setupinteraction[state=start] \starttext \startTEXpage[offset=1em] \definefield[x][signature] \field[x] \stopTEXpage \stoptext I can only use Acrobat to sign PDF documents with signature fields generated by ConTeXt. Other tools sign the PDF document not producing a valid signature (Acrobat cannot read or validate it). From the source, signature has two objects (copied from the sample above): 2 0 obj << /DA (/rmtf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG) /DV <FEFF> /F 4 /FT /Sig /Ff 0 /Kids 1 0 R /MaxLen 1024 /Q 0 /Subtype /Widget /T <FEFF0078> /V <FEFF>

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endobj

4 0 obj << /Type /Annot /DA (/rmtf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG) /F 4 /Parent 2 0 R /Q 0 /Subtype /Widget /Rect [ 14.033054 14.033054 70.40415 25.08072 ]

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endobj

One of the tools that has issues with two objects for the signature field is the latest version (1.18) from mupdf-gl. mupdf-gl adds the signature value to the child (object 4) and not to its parent (object 2). I’m afraid this is also the same issue that AutoFirma (a e-signing tool developed by the Spanish government [https://firmaelectronica.gob.es/Home/Descargas.html]) has with these signature fields. When both objects are merged in one (as Acrobat Reader does when saving a copy), both tools generate documents contaning signatures totally unproblematic to be read validated by Acrobat. I suggested merging both objects back in 2017. You told me that simplifyng this would introduce too much complexity in ConTeXt only to save some bytes. Back then, I thought it was an minor improvement. Now I realized that this two objects for signature fiels are only valid for Acrobat. I wonder whether this improvement might be also easier to make in LMTX. Would it be possible that signature fields may have only one object, so that mupdf-gl and other tools have no problem signing fields PDF documents generated by ConTeXt? Many thanks for your help, Pablo -- http://www.ousia.tk