Good idea on setting off requirements in a text box; we may find there are other types of content to highlight in other kinds of boxes (deprecated practices, optional provisions, etc.).
I think there's a way to make the "Please note" section a little more clear. Something like:
"These standards have evolved over time, and there may be official parts in the LDraw.org Parts Library that do not conform to these requirements. Such parts need not be edited and re-submitted solely for the purpose of bringing them into compliance. However, all parts submitted to the Parts Tracker, whether new parts or fixes to existing official parts, must conform to the current library requirements."
I think there's a way to make the "Please note" section a little more clear. Something like:
"These standards have evolved over time, and there may be official parts in the LDraw.org Parts Library that do not conform to these requirements. Such parts need not be edited and re-submitted solely for the purpose of bringing them into compliance. However, all parts submitted to the Parts Tracker, whether new parts or fixes to existing official parts, must conform to the current library requirements."