noun
stored message summary; MS
Computing term for a count or summary of stored messages, often abbreviated as MS in technical contexts.
システムの格納メッセージ該当数を確認してください。
Please check the stored message summary count in the system.
Compound of 格納 (storage), メッセージ (message), 該当 (applicable), and 数 (number). The exact derivation is uncertain; it is a technical term likely coined in computing contexts.