Letters that make countersignature
s, a, o, e, g, n, c, r, t, i, u are letters that make 'countersignature'
Words within countersignature
ER, nature, sign, signature, countersign, re, te, si, NT, UN, at, SI, counter, count, gnat, Ur, CO, Re, At, Co, Er, Si, Na, Te, Ig are words within 'countersignature'