> They handle big-endian data. What is "true" big-endian?

That's the second time you ask this same question to me. And it's now the second time that I will answer it, or better: refer you to my answer from 5 months ago:

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=11&topic_id=6726&start=119

:-)

> why does it matter?

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=11&topic_id=6726&start=90