IEC 60061 Lamp caps and holders together with gauges for the control of interchangeablility and safety consists of four parts: Part 1: Lamp caps, Part 2: Lampholders, Part 3: Gauges, Part 4: Guidelines and general information. Each part is independent of the other, but a given part should always be studied in conjunction with the other parts. This consolidated version of IEC 60061-1 is based on the third edition (1969) and its supplements A(1970), B(1971), C(1972), D(1972), E(1972), F(1975), G(1977), H(1977), J(1980), K(1983), L(1987), M(1989), N(1992), P(1994), Q(1994), R(1995), S(1996), T(1996), U(1996), V(1997), and amendments 21(1998), 22(1999), 23(1999), 24(2000), 25(2001), 26(2001), 27(2001), 28(2002), 29(2002), 30(2002), 31(2003), 32(2003), 33(2003), 34(2004) and 35(2004). It bears the edition number 3.35.