PDF/A-2 imposes implementation limits on integers, floats, strings, names, indirect object count, q/Q pairs in content streams, numbers of colorants in a DeviceN space and CID values. Export to PDF/A needs to fail if any of these limits is exceeded.

Some of these are enforced by pdf-writer through the type system. We always explicitly write DeviceN colorants (never > 4) and the number of CID values depends on the glyph count in the font (OpenType fonts never contain more than 65535 glyphs).

However, the following could arise through user input and need to trigger an alert at the export stage.

• Strings longer than 32767 bytes
• Names longer than 127 bytes (e.g. when containing font name)
• More than 8388607 indirect objects
• More than 28 q/Q nesting level

This depends on #2943. However, inroads here could be made by tracking e.g. nesting level and indirect object count without reporting in a first PR.