Hafid Ibn Hajar Asqalani (may Allah Almighty have mercy upon him) writes in Nukhbat al-Fikr:

الحمد لله الذي لم يزل عليماً قديراً وصلى الله على سيدنا محمد الذي أرسله إلى الناس كافةً بشيراً ونذيراً، وعلى آل محمد وصحبه وسلم تسليماً كثيراً. أما بعد:

All praise is to Allah who never ceases to be knowing and able. Peace be upon our master Muhammad who was sent to the people [as a person bearing] glad tidings and warning. [Blessing be] upon the family of Muhammad and his companions. Let there be abundant salutations upon them.

فإن التصانيف في اصطلاح أهل الحديث قد كثرت، وبسطت واختصرت، فسألني بعض الإخوان أن ألخص له المهم من ذلك، فأجبته إلى سؤاله رجاء الاندراج في تلك المسالك.

Indeed writings on the terminologies of the experts of Hadith has become many, been expanded upon and summarised. So some brothers have requested me that I summarise for them the pertinent from these. So I responded to their request in the hope of being included among these type of people.