Each user can create as many custom signatures as they want. You can have a default signature go out with every message or choose not to include a signature at all. When composing a message, you can also add different signatures to each message.
To create a Custom Signature:
1. Open your User Profile.
2. Click the Edit Profile button.
3. Click the Add Signature button under the Preferences tab.
4. Enter whatever you’d like your signature to be.
5. Click Save when you’re done.
6. Repeat steps 2-4 until you’ve created all the signatures you want. You can delete or update these signatures at any time.
7. Click the circle next to the signature you want to set as your default.
8. Check the Auto Add Signature to All Messages box if you want your default signature included with every message you send.
Note: Signatures are saved to individual user profiles. If you enable a signature to add to all of your sent messages, that signature only appears on messages sent by your user profile and no one else's on the dashboard or account.
How To Send a Custom Signature
Clicking the Signature Icon whenever you're composing a new message will open the list of pre-saved signatures you've created. This can be done in a brand new message or as a reply in a Conversation Block.
To add a Signature to a new message:
1. Click Compose Message.
2. Type your message.
3. Click the Signature button.
4. Click the Signature you want to add to this message.
5. Click SEND to send your message with the signature. 
To add a Signature to a reply:
1. Click on the Conversation Block you’re looking for.
2. Click the message bubble and type your reply.
3. Click the Signature button.
4. Click the Signature you want to add to this message.
5. Click SEND to send your message with the signature.
Note: Before sending the message, you can choose a different signature to attach by clicking a different signature from the list of your saved signatures, or delete the signature by clicking None.