By default, feeds on MyGet can contain any package that is added or pushed to them. Starting MyGet 1.6, we’ve added support for blocking certain packages from being added to your feed. To configure this, we’ve added a new tab on every feed.
This new tab currently features two options: “forbid overwriting of existing packages” and “forbid packages which are non-compliant with Semantic Version”. The first one is obvious: when enabled, MyGet will refuse overwriting existing packages on your feed. This makes it possible to achieve an important goal: have a guarantee that a given, known package is always exactly the same package in the future.
Enabling the “forbid packages which are non-compliant with Semantic Version” option allows you to block uploading of packages that are not SemVer compatible. Version numbers like 1.0.0 and 1.5.12559 will be allowed as well as 1.0.0-PRE. Package versions like 126.96.36.199 and 188.8.131.5269 will be blocked.