Board Thread:Questions and Answers/@comment-88.234.251.74-20161202132852/@comment-26484417-20161202134054

No, it's the so called "preview chapters". Since his most recent hiatus, SIU has introduced an option to purchase access to up to three chapters in advance. However, it's not simply an opportunity to view the content in advance, because SIU sometime changes, adds, or removes a thing or two between the "preview release" and the "final release". Currently, the 226 is the latest final release chapter, while 229 is the latest preview chapter.

This wiki follows only the final releases, and any content related to the preview releases is viewed as a spoiler and must be treated as such.

If you're interested in looking into the preview chapters some more, then I recommend you visit this thread on Bato.to.