When you inherit a shared drive, take over a project, or receive files from a source that no longer responds, you often end up with documents whose origin you cannot confirm. The first useful step is to give these files a label that makes their uncertain status visible at a glance. A simple convention works well: add a short prefix like "unverified" or "origin-unknown" to the filename, or place them in a folder whose name carries that meaning. The goal is not to create a permanent archive but to prevent these files from being treated the same way as materials whose source and accuracy you have already checked.
Once labeled, keep these files physically separate from your working set. This means a dedicated folder or directory rather than mixing them into project folders where teammates or future-you might grab them without noticing the gap in provenance. If your team uses version control or a document management system, consider whether that system lets you tag or flag items so the separation persists even if someone moves a file. The point is to reduce the chance that an unverified file gets cited, forwarded, or built upon as though it were confirmed.
Alongside each file, write down what you actually know and what you do not. A short text note or a simple spreadsheet row can record the date you received the file, who sent it or where you found it, and which specific details are missing. For example, you might know the file arrived in a particular email thread but have no way to confirm whether the numbers inside it were final or draft. Recording that gap honestly is more useful than guessing. This note also gives you a concrete list of questions to raise if you later reach out to the original source or a colleague who might clarify things.
Finally, decide in advance what will happen to these files once you get answers or once a reasonable waiting period passes. Some may turn out to be duplicates of verified materials and can be deleted. Others may be confirmed and moved into your normal structure. A few may remain unresolvable, in which case you can choose to keep them clearly marked or remove them entirely. Having this endpoint in mind from the start keeps the unverified pile from growing indefinitely and turning into a source of confusion rather than a manageable holding area.