Update with SemVer info

maintenance.rst

@@ -14,5 +14,19 @@ Keeping your ``fail2ban`` filters up-to-date is critical for the correct operati
 When to Update
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+Knowing when to update your filters has changed since 4.4.x. The release notes, as always, still say whether updating is necessary, but now that *WPf2b* strictly follows SemVer it's trivial to determine when an update is needed. In addition, the WordPress Site Health tool now checks if the filters are up to date.
+
+SemVer
+======
+
+From v5.0.1 to v5.0.2
+  You will never need to update the filters.
+
+From v5.0.x to v5.1.0
+  You may need to update the filters to enable new features; existing configurations will continue to work as before.
+
+From v5.1.x to v6.0.0
+  You may need to update the filters for existing features to work.
+
 How to Update
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