Class A: Identity Gating
User-Level FailuresNew Customer Exclusive
The merchant's logic checks your purchase history. The code is rejected if your email address or IP has completed a prior transaction.
Loyalty Tier Gate
Valid only for specific account segments (e.g., VIP, Gold Member). Requires authentication to verify tier status.
Class B: Cart Composition
Item-Level FailuresSale Item Exclusion
The code logic strictly voids the discount if the cart contains any SKUs already marked down (clearance/sale).
Brand Exclusion
Common in multi-brand retailers. Specific high-value brands (e.g., Apple, Nike) are hard-coded to reject sitewide offers.
Class C: System Constraints
Platform-Level FailuresStacking Conflict
The merchant platform (Shopify/Magento) allows only one "promo object" per session. This code conflicts with an auto-applied offer.
Geo-Fencing
The code is restricted to specific shipping zones or IP ranges (e.g., UK Only, Continental US).