[This question][1] from an experienced AU member was closed yesterday. I think it was a mistake to close it. The question is clear and the linked duplicate does not fully answer the original. 

Direct quote from the original: 

> "What I want is not only to forbid the package to update but to **save
> it for future installations too**. How can I achieve this?"

The duplicate only addresses the issue of locking the current package in the *current install*. It does not answer the question of how to save the package for a future clean install by reformatting the drive. Drive failure and recovery would be another reason to back up the package.

Can we get this reopened please? It needs a good answer involving copying the deb from `/var/cache/apt/archives`.

  [1]: https://askubuntu.com/q/169470/12864