Firstly: The Definition of the Prostration of Forgetfulness
The prostration of forgetfulness consists of two prostrations that make up for a shortcoming in prayer due to forgetfulness.
Secondly: The Ruling of the Prostration of Forgetfulness
The prostration of forgetfulness is wajib in general. This is the authentic position of the Hanbali  Ibn Rajab says: “However, Ahmad considers it wajib only in the case of making up for something whose intentional performance would invalidate the prayer. As for what does not invalidate the prayer if done intentionally – such as the non-performance of sunnah acts and the performance of an invocation at the wrong place in prayer (other than salams) – it is not wajib according to him.” (Fath al-Bari, 6/515) and Hanafi schools, and one position among Malikis. It is the position of al-Thawri, Ibn al-Mundhir, and Ibn Hazm. It was chosen by Ibn Taymiyyah, Ibn Baz, and Ibn `Uthaymin.
Thirdly: Who is Obliged to Prostrate Due to Forgetfulness
The prostration of forgetfulness is the duty of one praying alone and the imam.  As for the prostration of forgetfulness for a follower, it will be covered in Section VIII. Consensus on this was related by Ishaq ibn Rahawayh, Ibn Rushd, Ibn Qudamah, and al-Nawawi.
Fourthly: The Prostration of Forgetfulness for One Who Suffers from Chronic Doubts
One who suffers from chronic doubts does not perform the prostration of forgetfulness due to mere doubts in their prayer. This is by agreement of the four schools of jurisprudence.