As a mature writing, what did Oracle Bone Inscriptions mainly record?

From the beginning, Oracle Bone Inscriptions had a basic form (the structure of later Chinese characters), which was a relatively mature writing.

Judging from Oracle Bone Inscriptions's writing structure, Oracle Bone Inscriptions already has the traditional so-called "Six Books", namely pictographic characters, knowing characters, indicating words, pictophonetic characters, loanwords and annotations.

It mainly refers to the characters carved on tortoise shells or animal bones by the royal family in China in the late Shang Dynasty (14 ~1century), which is the earliest known systematic writing form in China. Today's Chinese characters are also related to Oracle Bone Inscriptions.