GUIDE · DESIGN PREVIEW
旧备份里，可能保留了什么？
What can an old backup tell you?
先看时间与包含范围
删除前的备份可能保留目标内容，但必须实际检查；不能只凭备份日期就认定里面一定有照片或消息。
An earlier backup may contain the item, but it must be inspected. The date alone does not prove a photo or message is present.
先保护原始备份
应保留原始备份，分析与导出尽量在副本上进行。加密备份需要合法持有人提供可用密码。
Keep the source backup and work on a copy where possible. Encrypted backups need a usable password from the authorized owner.
部分采集要明确标记
缺少文件或未通过完整性验证的采集，不能称作完整备份。缺少附件时，消息文字可读不代表照片或视频也可导出。
A partial or unverified acquisition is not a complete backup. Readable message text does not prove its photo or video attachment is available.