Some types of data, like coupons, have a limited duration. In other cases you may just want to limit the time an item is listed in your directory, either to encourage freshness or encourage people to pay to keep the listing longer.

The 'expirations' switch enables/disables the option to set an expiration date for images on the 'submit image' or 'edit image' pages. Normally this will be done by directly typing a date or number of days, but by checking the 'incriment options' subswitch you can presents a dropdown selector from which the user will choose a number of days to expiration or a number of days to renew for.

In the usergroup permissions you can specify for each usergroup how many times they can renew an expired image, and for how many days. The days set here will also be used to determine the selector values when you have the 'incriment options' switch on, unless you set a default days to expiration. In order to renew the user will simply edit the image and select the radio button to renew.

At Admin -> Settings -> Images you can set a default number of days to expiration which will apply to new images unless overridden.