Documentation for JIRA 6.4 EAP. Not using this? See below:
(JIRA 6.3.x documentation | JIRA Cloud documentation | earlier versions of JIRA)

Title: Attaching a Screenshot  
Author: admin Apr 17, 2009
Last Changed by: Warren Thompson May 13, 2014
Tiny Link: (useful for email) https://confluence.atlassian.com/x/DgISCw
Export As: Word  
Incoming Links
JIRA 5.1 (1)
    Page: Viewing your System Information
JIRA 6.4 EAP (4)
    Page: Attaching a File
    Page: Viewing your System Information
    Page: JIRA 6.2.5 Release Notes
    Page: Configuring File Attachments
JIRA 5.0 (1)
    Page: Viewing your System Information
JIRA 4.2 (1)
    Page: Attaching a File
JIRA 6.2 (1)
    Page: JIRA 6.2.5 Release Notes
JIRA 4.3 (1)
    Page: Attaching a File
JIRA 4.1 (1)
    Page: Attaching a File
JIRA Knowledge Base (1)
    Page: JIRA cannot save attachments due to No space left on device
Hierarchy
Parent Page
    Page: Working with an Issue
Labels
Global Labels (3)
Outgoing Links
JIRA 5.1 (1)     Page: How to enable "Attach Screenshot" on Linux Machine
JIRA 6.4 EAP (4)     Page: Managing Project Permissions
    Page: Configuring File Attachments
    Page: Attaching a Screenshot
    Page: Attaching a File