YAML Format for meta: what does `PluginImporter` mean?

Working with teammates on my project, with us having the same Unity version but heterogeneous hardware (Mac, Windows, Linux…), there are some times where a whole bunch of meta files get changed and ready to get committed. The changes look like this:

    --- a/Client/Assets/Plugins/iOS/Reachability.h.meta

    +++ b/Client/Assets/Plugins/iOS/Reachability.h.meta

    @@ -1,4 +1,30 @@

    fileFormatVersion: 2

    guid: 59f3a46e1d9a63449bbc3ff968e8c7e8

    -DefaultImporter:

    +PluginImporter:

    +  externalObjects: {}

    +  serializedVersion: 2

    +  iconMap: {}

    +  executionOrder: {}

    +  isPreloaded: 0

    +  isOverridable: 0

    +  platformData:

    +  - first:

    +      Any:

    +    second:

    +      enabled: 0

    +      settings: {}

    +  - first:

    +      Editor: Editor

    +    second:

    +      enabled: 0

    +      settings:

    +        DefaultValueInitialized: true

    +  - first:

    +      iPhone: iOS

    +    second:

    +      enabled: 1

    +      settings:

    +        AddToEmbeddedBinaries: false

        userData:

    +  assetBundleName:

    +  assetBundleVariant:

My question is, what does that `PluginImporter` section mean? Also, wondering but what about the `serializedVersion`?

Thanks in advance

 

The file Assets/Plugins/iOS/Reachability.h is a plugin that unity can use on IOS.
For each plugin there is a set of option you can choose like witch platform you like to use the plugin on.
This settings are set via the PluginImporter.
If you did not change anything on it it should not have changed.