What does 書き込み mean?
書き込み is a Japanese noun meaning “writing” in English. It can also be translated as “entry (e.g. to a form), posting (e.g. to a blog)” depending on context. It is written as 書き込み in kanji, かきこみ in hiragana, and kakikomi in romaji. This word is part of JLPT N2 vocabulary.
Example sentence
そのフロッピー、念の為書きこみ禁止にしておいて。
Make that floppy uncopiable, just in case.