I got stuck with a PDF-Document, which (among other fields) contains five larger multiline text-inputs. For all five fields the DefaultAppearance-parameter of the relevant widget says
/DA (/SimplonNorm 0 Tf 0 g)
Is this a bug, a feature, or an unintended slip by the person who designed this PDF-Form?
As a matter of fact, this font size zero would result in invisible text once the document gets printed. To my observation, different PDF-viewers/writers (firefox,chromium,ubuntu-document-viewer) seem to substitute this zero-value by an obviously arbitrary new font-size. This, in turn, results in different rendering of the input-field, depending on the tool by means of which the form-fields get filled.
I am working on a php-tool to automatically fill this form, and a bit unsure whether I just choose an arbitrary value myself, or whether we should additionally contact the government agency who designed it.