What is the prohibited method of improvisation in poetry, is rap included in it, and what are the topics that are not permissible to mention in it?

The blameworthy topics of poetry in the Prophetic Sunnah, which are impermissible to address, are those that include forbidden elements, such as: singing, composing amorous poetry about women, describing wine, lying, slandering, and satirizing. However, poets who do not engage in such practices are exempted, as Allah the Almighty says: "And the poets - [only] the deviators follow them. Do you not see that in every valley they roam and that they say what they do not do? Except those who believe and do righteous deeds and remember Allah much and defend themselves after they have been wronged." (Ash-Shu'ara: 224-227).