Subject: Re: [docbook-apps] WARNING: Glyph "?" (0xfffd) not available in font "Frutiger-LightItalic".
This is a bit of a mystery. The Unicode character xFFFD is the Replacement Character, which the Unicode standard says is "used to replace an incoming character whose value is unknown or unrepresentable in Unicode". You won't find that character in the DocBook stylesheets, nor will you find it any font.
I see that character in the edit window of the UniPad editor sometimes, but I don't think that character is actually in the file. It usually represents a mismatch between the encoding and the bytes in the file.
The footer content with a separator character that you describe is not the stock footer, because it does not display any heading. I presume that footer is coming from your customization layer. What does that look like? Have you taken a peek inside the FO output to see what character is in the file?
When you upgraded from DocBook 4.5 to 5.0, did you also start using the namespaced version of the stylesheets? I'm trying to figure out what exactly changed here.