The RTA label, short for Restricted To Adults, is a free voluntary tag a website places in its own code, either as a meta tag in the page head or as an HTTP response header, to flag that a page or asset carries adult content. Parental control filters and operating system controls read the tag and can then block the page for minors. It is published by ASACP, the Association of Sites Advocating Child Protection.
Why it matters
The RTA label is a labeling standard, not age verification, and the difference decides real money for adult merchants. The label describes the page so a filter on the visitor’s device can block it. It never checks who the visitor is, so it satisfies no US state age verification law and not the UK Online Safety Act. What it does buy is trust at underwriting. No card network rule names RTA, but acquirer and adult PSP site reviews look for it beside an 18 plus warning page and a 2257 statement, folding it into content expectations like BRAM. It is the cheapest signal of operator maturity a high risk merchant account applicant can add, which is why skipping the free label still costs you when a reviewer boards your site.