2.3.1 is the “accurate metadata” rule. Reviewers compare what you show in the store with what the IPA actually does and contains. Hidden modes, leftover brands, and screenshots from another build are the usual reasons this code appears, often beside 4.3.
Hidden or leftover features
A debug menu, a second skin, or an old game mode that still launches from a gesture will be treated as a feature you did not declare. If you do not want it reviewed, remove it from the binary. Obfuscating the selector name is not a substitute for removal.
Screenshots and preview video
Capture from the exact build you upload. Do not reuse marketing frames that include buttons the current target does not compile. If you localized the UI, screenshots should match the primary locale you submitted.
Resources and strings
Search the IPA for previous product names, old Bundle Ids, and URL schemes. Icon sets and Info.plist display names are frequent leftovers when a project is cloned. Crab can rename and encrypt resources so those strings are not sitting in the obvious places; you should still delete unused brand assets. See the 2.3.1 page.
Pre-submit list
Listing matches binary. No hidden entry points. No foreign trademarks in assets. Support URL works. If you also look like a duplicate app, do the 4.3 self-check. Docs for running the tool: crab-ios.com/docs/site.
Request a trial, then archive and submit
Download App Center, choose the General or Uni-app edition, then apply for a license on the registration-code page. The docs cover the operator steps.