Universal 842:

Original: There are no initial or final clusters in which all obstruent combinations are heterogeneous in regard to voicing.
Standardized: There are no initial or final clusters in which all obstruent combinations are heterogeneous in regard to voicing.
Keywords: consonant cluster, obstruent, heterogeneous, voice
Domain: phonology
Type: unconditional
Status: achronic
Quality: absolute
Basis: sample of 104 languages in Greenberg 1964
Source: Greenberg 1964 [Greenberg 1965: 13, Greenberg 1978e: 252, #5]

Counterexamples: Modern Hebrew has no restrictions on this. Compare the feminine adjectives: ‘ktuma’ (orange(-coloured)), ‘kduma’ (ancient), ‘gduma’ (amputated), or ‘tguwa’ (reaction) vs. ‘tkufa’ (period), where the initial clusters are all distinct (Hetzron 1980: 263).

FP