Standard PDF permission flags work in Adobe Acrobat and most compliant readers. However, some third-party readers may ignore the restrictions, so permissions are best treated as a deterrent rather than an absolute guarantee — combine them with password protection for stronger control.
後で権限を変更または削除できますか？
Yes. As long as you know the owner password you set, you can re-open the file with this tool and apply new permission settings, or remove restrictions entirely by clearing all toggles and re-encrypting without limits.
PDFを表示するために受取人にパスワードは必要ですか？
No. By default, this tool leaves the user password empty so anyone can open and read the document. Only the owner password is set, which controls actions like printing and copying once the file is opened — viewers never see a password prompt.