The Rule of the Restriction Particle innamā

According to the grammar rule, what effect and purpose does إِنَّمَا have in a sentence?

Support for the Religion, Restriction, and the Rules of innamā (Hadith 110-114)

• It creates negation and makes the following noun jussive
• It creates restriction and completely prevents inna from making the following noun accusative
• It turns the sentence into a question
• It makes the noun genitive