• At first sight, the sum of prescriptions seems to amount to a recipe (You ought to do x, You ought to do y, You ought to do z…), with just a linear sequence of successive orders
• Almost all actions are accompanied by mantras

The latter characteristic, historically, means that the Śrautasūtras have been composed around pre-existing mantras, in order to supply the actions which the sacrificers knew were to be performed together with the mantras. Another interesting feature of the presence of mantras is that this does not amount to

O p & m
(with O meaning “Ought to”, p being the action prescribed and m the mantra)

because the choice of the mantras also often depends on what one has already performed. In other words, the whole sacrifice as prescribed rather resembles a flowchart, in which one might need to go back and forth:

In No. 1, the disjunction is determined by one’s history previous to the sacrifice. If one is entitled to perform a certain sacrifice, one will have to perform a certain offering, otherwise another one. The ŚrSū explain this by saying “If one is a certain type of sacrificer, then…”.