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Matches a pair of http:// URLs on the same non-www domain that share an identical .htm/.html filename but sit under different single-letter path segments (u, c, or v). The first URL must be preceded by 3 blank/whitespace-only lines, and the second must appear after 5-50 blank lines, with up to 100 chars of non-slash text before it. Typically used in spam or phishing filters to catch email/message bodies containing mirrored download links hidden under varying path prefixes on one host.