Important signs and terms are taught since the first day of university. Consequently, all of the architecture professors and students, know and understand a universal language of symbols and words. Yet, some of the signs are easy to understand for everyone. For example, the walls and the stairs. But, some of the more professional, can be read only by the constructors and the architects. It is very significant for them to learn all of these, and to know how to use them, because it is all an unified architecture language.
Important Graphic Standards
Finally, the signs on these pictures make the life of the professionals easier and less complicated. See the link below for more information.