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[Ian_Chimp]

You can indeed lose the Regular status if you stop being a forum regular:

@Lovehoney_Brenna

Furthermore, unlike other trust levels, you can lose trust level 3 status. If you dip below these requirements in the last 100 days, you will be demoted back to Member. However, in order to avoid constant promotion/demotion situations, there is a 2-week grace period immediately after gaining Trust Level 3 during which you will not be demoted.