na-adjective, noun
Used to indicate that something is identical to what was just mentioned, often in lists, forms, or casual conversation. Functions as a noun or adjectival noun.
前回と同断の内容です。
The content is the same as last time.
住所は同断。
The address is the same.
Compound of 同 (same) and 断 (decision, judgment). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning 'the same'.