Rule (Stage C, months 2–12): let trust accrue, don't panic — keep `<lastmod>` honest, expect ranking volatility as Google "making assumptions" not a penalty, do NOT buy aged domains or sandbox-escape services

Rule: Stage C — months 2–12. Let trust accrue; don't panic:

• Keep <lastmod> honest. Update it only on substantive changes. Don't churn dates to bait crawls — it erodes trust (Rule: update sitemap <lastmod> only on substantive content changes — churning the date erodes Google's trust in the signal).
• Expect ranking volatility and interpret it as Google "making assumptions" (Mueller (May 28, 2021 SEO office hours) on new-site ranking instability — "we don't have a lot of signals for that new content yet… we have to make assumptions"), not a penalty.
• Do NOT buy aged domains, indexing services, or "sandbox escape" packages (Rule: do not buy aged domains, "instant indexing" services, or "sandbox escape" packages — the causes they address are not real).
• If a broad core update hits during year one and rankings drop, treat it as a relative re-weighting: improve helpfulness/depth/experience on the specific pages that slipped; expect full re-evaluation to land with the next core update (Broad core updates are NOT penalties — Sullivan: "this doesn't mean all sites will go back up to wherever they were if they are down from a previous peak"; recovery requires substantive improvement + waiting for the next update; 2026 cadence: March 27–April 8 + May 21–June 2).

Why: Year-one volatility is the rule, not the exception. The single biggest unforced error is over-reacting — switching themes, buying aged domains, hiring "sandbox escape" vendors — which interrupts the trust-accrual signal Google is trying to build.

How to apply (threshold): If important pages remain unindexed after ~4 weeks despite good content and clean technicals, escalate to a content-quality and internal-linking audit rather than re-requesting indexing repeatedly (Rule: if important pages remain unindexed after ~4 weeks despite good content and clean technicals, escalate to a content-quality and internal-linking audit — do NOT just keep clicking "request indexing").