Oracle WebCenter Sites 184.108.40.206.0 came with significant improvements to the product. Many customers use this version to deliver their web presence. It came certified with several versions of Oracle Database—11g R1, 11g R2, and 12c R1. While the customers upgrade their tech stack to the latest, it's quite possible that they upgrade Oracle Database while continuing on WebCenter Sites 11g. We updated the database certification for such scenarios to include Oracle Database 12c R2 (220.127.116.11+). Refer the official certification matrix for WCS 11g R1 for more information. The database certifications are listed under 'WCS on WLS - Database' sheet.
WebCenter Sites 12c R2 is available since October 2015 with a whole slew of capabilities and features to build superior digital experiences for your customers. Upgrading your WebCenter Sites 11g is vastly streamlined including silent install and automated upgrade assistant. It is highly recommended to upgrade to WebCenter Sites 12c. Refer Oracle Lifetime Support Policy for Oracle Fusion Middleware Guide for more information on planning and budgeting the upgrade based on the support timelines for WebCenter Sites 11g, specifically 18.104.22.168.0.
With the recently introduced DataDiff Migration Tool, upgrade can be planned to execute in a phased manner. After the initial upgrade, content contributed into the 11g system may be migrated into the 12c system, which is still being tested, readied by the developers and admins. This helps you test your 12c system, end-to-end, with your 11g production data. Once 12c system goes live, Contributors will begin contributing into the 12c system and you may shutdown the 11g system.