You're right to be curious about that! The naming convention for compounds with oxygen can seem a bit counterintuitive. Here's why fluorine compounds with oxygen are called fluorides:

* Electronegativity: Fluorine is the most electronegative element on the periodic table. This means it has a stronger pull on electrons than oxygen does. In a compound like OF2 (oxygen difluoride), fluorine is actually pulling electrons away from oxygen.

* Anionic Nature: Because fluorine is more electronegative, it tends to gain electrons and form a negative ion (fluoride ion, F-). Oxygen, on the other hand, would be the positive ion in this situation.

* Naming Conventions: The traditional naming convention for binary compounds (compounds with two elements) places the more electronegative element second and adds the suffix "-ide" to its name.

Therefore, in a compound like OF2, the fluorine is considered the anionic element, and it is named as the "fluoride" portion of the compound.

It's important to remember that naming conventions are established for clarity and consistency. While it might seem odd at first, this system ensures that we can accurately and easily identify and distinguish between different chemical compounds.