# Entity Tags

*Entity tags provide a flexible way to organize and group entities across your simulation project for easier management and selection.*

## Overview

Entity tags allow you to apply custom labels to entities in your project, enabling:

- Logical grouping of related entities regardless of their type
- Quick selection of multiple entities with the same tag
- Organization of complex simulations with many entities
- Filtering and searching for specific entity groups

## Creating and Managing Tags

### Creating a New Tag

1. Navigate to the **Entity tags** section in the Entities browser
2. Click the **"+"** button to create a new tag
3. Configure the tag parameters
4. The tag is now available and entities matching the expression are automatically tagged

### Tag Parameters

| *Parameter* | *Description* |
|-------------|---------------|
| **Name** | A descriptive name for the tag |
| **Description** | Optional description explaining the purpose of the tag |
| **Type** | The entity type to tag (e.g., Surface, Volume, Point, etc.) |

### Tagging Entities via Expression

Tags can automatically include entities based on expressions. This allows you to dynamically tag entities that match specified criteria.

#### Expression Builder

Each expression condition consists of:

| *Component* | *Description* |
|-------------|---------------|
| **Property** | The entity property to filter on (e.g., **Name**) |
| **Operator** | The matching operator: **matches** or **not matches** |
| **Value** | The pattern to match against (supports wildcards, e.g., `*wing*`) |

#### Combining Conditions

- Use the **And** / **Or** toggle to control how multiple conditions are combined:
  - **And** - Entity must match ALL conditions
  - **Or** - Entity must match ANY condition
- Click **+ Add** to add additional filter conditions
- Click the trash icon to remove a condition

### Applying Tags Manually

Tags can also be applied to individual entities through:
- The entity's properties panel (via the **Tag** field)
- Selecting an entity and assigning it to an existing tag

## Use Cases

### Boundary Condition Groups
Tag all surfaces that share the same boundary condition type for easy identification and modification.

### Output Selection
Tag entities that should be included in specific output configurations (e.g., all surfaces for force calculation).

### Refinement Regions
Tag volumes and surfaces that require similar mesh refinement settings.

### Component Organization
In multi-component assemblies, tag entities belonging to each component (e.g., "fuselage", "wing", "tail").