# Providing Specification Information and Descriptions

Descriptions on the **Specification** tab describes a root definition and its attributes and methods.

In the Component Library, the **Specification** tab renders descriptions from your .cmp, .evt, or .intf file. For instance, see the Specification tab for `lightning:avatar` at [https://developer.salesforce.com/docs/component-library/bundle/lightning:avatar/specification](https://developer.salesforce.com/docs/component-library/bundle/lightning\:avatar/specification).

HTML markup is not supported in inline descriptions.

The specification information is generated based on the root-level tag, which looks like this.

```xml
<aura:component
    access="global"
    implements="lightning:myInterface"
    minVersion="41.0"
    description="A collection of vertically stacked sections with multiple content areas. This component requires version 41.0 and later.">
    
```

The specification information includes:

## Access Level

Only root definitions, attributes, and methods marked with `access="global"` are surfaced in the Component Library.

## Abstract

A root definition with `abstract="true"` denotes that it’s abstract. An abstract component can’t be used directly in markup. The default is `false`.

## Extensible

A root definition with `extensible="true"` denotes that it’s extensible, which makes it a super component. A sub component that extends a super component inherits the attributes of the super component. The default is `false`.

These tags support inline descriptions via the `description` attribute.

## `<aura:component>`

The root definition tag in a component .cmp file.

```xml
<aura:component description="Represents a button element.">
```

## `<aura:event>`

The root definition tag in an event .evt file.

```xml
<aura:event type="COMPONENT" 
    description="Indicates that a key has been pressed.">
```

## `<aura:interface>`

The root definition tag in an interface .intf file.

```xml
<aura:interface name="label" 
    type="String"
    description="A common interface for date components.">
```

## `<aura:attribute>`

An attribute tag in a component, event, or interface file.

```xml
<aura:attribute name="label" 
    type="String"
    description="The text to be displayed on the button.">
```

## `<aura:method>`

A method tag in a component , event, or interface file. Each method tag can contain multiple attribute tags.

```nolang
<aura:method name="setCustomValidity" description="Sets a custom error message.">
  <aura:attribute name="message" type="String"
      description="The string that describes the error. If message is an empty string, the error message is reset."/>
</aura:method>
```