Glyph Not Available in Font

Problem

A warning appears during the PDF transformation that is similar to this:

[CH] Glyph "?" (0x2192, arrowright) not available in font "Roboto-Bold".

Warning: Even if the message is a warning, sometimes it can lead to a failed transformation. This usually occurs for unique special characters (different from letters or common characters).

Cause

Some fonts lack specific characters, such as CJK characters or Greek symbols commonly used in scientific publications. Those characters are replaced with the # symbol in the PDF output.

Solution

Specify one or more fallback font(s) in your customization CSS:

body{
  font-family: Roboto, Symbol, Arial Unicode MS;
}

Tip:

It is possible to use a generic family name as fallback (like serif, sans-serif or monospace) to call upon the processor's default fallback fonts system.
To determine the needed font, you can copy the text fragment from the DITA source document and paste it into any text editor (e.g. MS Word). Make sure there are no licensing restrictions on that particular font.