Analysis of the second differences of the level energies, A 2 £ rot (J), for the negativeparity bands with only odd spins in 236 » 238 u, 218 Ra, and 156 Er shows, at least for / ^ 7, a A/= 4 alternating energy-shift term. Such an unusual signature term is not expected in the framework of the quadrupole deformation model. PACS numbers: 21.10.Ft, 21.10. Re, 21.60.Ev, 27.90.+b In the vast lore collected about nuclear rotational bands, alternating energy-shift terms (signature terms) are well known for K± 0 bands. 1 In these bands levels of all spins, K, K + l, K+2, etc., are present. The signature terms were first recognized in Jf = l rotational bands and subsequently identified more generally. They can be understood in terms of Coriolis band mixing in various orders. 1 Bohr and Mottelson 1 give a general expression as follows: