In an article in Irish Central dated October 5,2013, subtitled by Jane Walsh "An Post honors Volunteers who were central to the 1916 Easter Rising" states:
An Post Stamps - Irish Volunteer Force
An Post, Ireland’s national postage service, has issued a stamp to commemorate the centenary of the Irish Volunteer Force.
The 60c stamp features a group of Irish Volunteers from Waterford by A.H. Poole Studio Photographers, and was shared by the National Library of Ireland.
In the six years of their short existence the Irish Volunteer Force helped shape the course of Irish history and left behind a legacy that lives on to this day. The Irish Volunteers were formed to defend the application of the Home Rule Bill to the whole of Ireland.
However, with the outbreak of World War I, the implementation of Home Rule was deferred. This led to a split in the Irish Volunteers. The majority formed the National Volunteers and went to Europe to help Britain in its war effort, believing this was the best way of achieving Home Rule.
The remaining Irish Volunteers, led by Eoin MacNeill stayed in Ireland. It now contained many Irish Republican Brotherhood members who were intent on striking against Britain while it was distracted by the war. MacNeill opposed a rebellion, but was tricked into supporting their plans. The rising took place at Easter 1916, but was a failure. In the aftermath, the Irish Volunteers were forced underground where they reorganized. In the War of Independence which began in 1919, the Irish Volunteers became known as the Irish Republican Army.