Documentation "Serializing Qt Data Types" incomplete

The documentation chapter "Serializing Qt Data Types" is pretty incomplete. QDataStram is an ideal interface to other system (e.g. via TCP/IP) and it should be possible to program a corresponding class for other languages/OSs without many hours of trial/error, debugging and guessing.

First, QChar documentation references the "Serializing Qt Data Types" chapter but when following the link "Serializing Qt Data Types" doesn't say something about QChar.

Second, understanding how a QVariant serialization works is simply not possible by documentation. What does the null flag exactly means? What is the difference between a set null-flag and a datatype "Invalid"? What is serialized for QVariant()? What is serialized for QVariant(QString()?
This is also true for other Qt classes.

The documentation should be MUCH more verbose (especially for complex types)!

BTW I tried to re-engineer QVariant serialization and found that a null-flag set to 1 and the datatype set to "Invalid" seem to mean the same thing. Is this true?