Okay, this is a great, concrete example to discuss! Let's look at your ElectricalComponentCategorySpecificInfo message:

// Metadata specific to a microgrid component.
message ElectricalComponentCategorySpecificInfo {
  oneof info { // <-- This is the oneof in question
    frequenz.api.common.v1.microgrid.electrical_components.Battery battery = 1;
    frequenz.api.common.v1.microgrid.electrical_components.EvCharger ev_charger = 2;
    frequenz.api.common.v1.microgrid.electrical_components.Fuse fuse = 3;
    frequenz.api.common.v1.microgrid.electrical_components.GridConnectionPoint grid = 4;
    frequenz.api.common.v1.microgrid.electrical_components.Inverter inverter = 5;
    frequenz.api.common.v1.microgrid.electrical_components.VoltageTransformer voltage_transformer = 6;
  }
}

The containing message is ElectricalComponentCategorySpecificInfo. This tells us that the message holds information specific to a component category. The oneof then provides the actual data for one of those specific component types.

Let's evaluate the current name info and some alternatives:

1. info (current):

   • Access path: ...category_specific_info.info.battery
   • Pros: Short.
   • Cons: It's a bit redundant. "Electrical Component Category Specific Info's info" sounds like "the information of the specific information." While not terrible, it could be more distinct.

2. kind:

   • Access path: ...category_specific_info.kind.battery
   • Pros: This is a standard and widely understood convention for oneof fields that act as discriminated unions, indicating the "kind" of data present. It signifies that the specific info can be of the kind "battery," "ev_charger," etc.
   • Cons: It's a bit abstract.

3. type:

   • Access path: ...category_specific_info.type.battery
   • Pros: Similar to kind, very common. It clearly indicates that this field determines the specific type of the component information.
   • Cons: Also somewhat abstract.

4. component:

   • Access path: ...category_specific_info.component.battery
   • Pros: This is quite descriptive in your domain. The oneof is literally selecting which specific component's detailed message is being provided. The fields within the oneof are battery, ev_charger – these are types of components. So, saying category_specific_info.component clearly points to "the actual component data within this specific info structure."
   • Cons: The word "component" is already part of the message name and the broader context (ElectricalComponent). However, this isn't necessarily a strong con, as it reinforces the domain concept.

5. details:

   • Access path: ...category_specific_info.details.battery
   • Pros: The oneof holds the details for the specific category. This avoids the "info.info" redundancy and is quite intuitive. "Category-specific info's details" makes good sense.
   • Cons: A bit more generic than component.

6. data:

   • Access path: ...category_specific_info.data.battery
   • Pros: Similar to details. The oneof contains the actual data payload for the specific category. Clear and common for payload-carrying fields.
   • Cons: Also somewhat generic.

Recommendation:

Given your specific structure and domain:

• Option A: component
  This is a strong contender. The oneof is selecting from different component types. category_specific_info.component.battery reads very naturally as "the battery component data within the category-specific information." It's domain-relevant and clearly indicates the nature of the choice.

• Option B: details or data
  These are also good choices. category_specific_info.details.battery emphasizes that this oneof provides the specific, detailed information for the category. It elegantly avoids the redundancy of the original info name.

• Option C: kind or type
  These are safe, standard choices that any Protobuf developer would immediately understand. They emphasize the polymorphic nature of the ElectricalComponentCategorySpecificInfo message.

My top recommendation would be component.

// Metadata specific to a microgrid component.
message ElectricalComponentCategorySpecificInfo {
  oneof component { // Renamed from 'info' to 'component'
    frequenz.api.common.v1.microgrid.electrical_components.Battery battery = 1;
    frequenz.api.common.v1.microgrid.electrical_components.EvCharger ev_charger = 2;
    // ... and so on
  }
}

This feels the most direct and semantically aligned with what the oneof represents: the specific component type whose data is included.

Second choice would be details:

// Metadata specific to a microgrid component.
message ElectricalComponentCategorySpecificInfo {
  oneof details { // Renamed from 'info' to 'details'
    frequenz.api.common.v1.microgrid.electrical_components.Battery battery = 1;
    frequenz.api.common.v1.microgrid.electrical_components.EvCharger ev_charger = 2;
    // ... and so on
  }
}

This is also very clear and avoids any redundancy.

Ultimately, the best choice is one that is clear to your team and consistent with other oneof naming in your project. However, based on the information provided, component seems to offer the best balance of domain-specificity and clarity for this particular oneof. info is acceptable but less ideal than these alternatives.