
Given the following passage

"Texts on architecture have been written since ancient time. These texts provided both general advice and specific formal prescriptions or canons. Some examples of canons are found in the writings of the 1st-century BCE Roman Architect Vitruvius. Some of the most important early examples of canonic architecture are religious.",

answer the following question. Note that the answer is present within the text.

Question: Ancient texts on architecture provide both formal prescriptions and what? 

general advice
