About Crow's foot notation (FFR):
https://en.wikipedia.org/wiki/Entity%E2%80%93relationship_model#Crow.27s_foot_notation
Entity–relationship model - Wikipedia
PS. UML now has equivalent diagrams, used for conceptual modelling (look for UML Domain Models, that show [domain] entities as classes with just a name).
Well, as the title states we'll be addressing software development topics (mainly in English). Topics will be quick and short and most probably aligned with the training "problems", sorry, programs I am involved in. PS. Some links are "internal" (not publicly available): If you are not able to reach it, google will find you a publicly available information source for sure. Happy trails to you.