After reading comments on https://codereview.qt-project.org/c/qt/qtdoc/+/428648 I thought it might be a good idea to now document the patterns and anti-patterns around setContextProperty in docs even though it was explained elsewhere. IMHO using setContextProperty is a popular approach to implementing a kind of global variables. If we believe it is not good for some reason, people should be able to read about this in the docs