¹ EOP provide the coordinate transformation from the International Celestial Reference frame to the International Terrestrial Reference frame.
²For the "individual" series the reference frame are not necessarily the international frames. The associated frames can present rotation with respect to the international frames up to a few milliarcseconds. See consistency.
³In order to compute UT1-TAI from UT1-UTC or inversely, we provide the offsets TAI-UTC and the associated FORTRAN software. UT1-TAI series can be also derived from UT1-UTC series by using this interactive tool.
⁴The celestial pole offsets (dψ ,d&epsilon) are referred to the precession-nutation model UAI 1980, but the offsets (dX,dY) are referred to the new conventional model UAI 2000. Presently all the available EOP time series provide (dψ ,d&epsilon), except one version of the combined EOP series C04 for the years 2002 et 2003 where we give (dX,dY) / UAI 2000. In the future (2005-2007) the series (dψ ,d&epsilon) / UAI 1980 will disappear for the benefit of (dX,dY) / UAI 2000. The transition from (dψ ,dε) / UAI 1980 to (dX,dY) / UAI 2000 or inversely can be achieved numerically by the software proposed by the EOP center. Some users may prefer the parameter (dψ ,dε)/ UAI 2000 , and then can use the approximation (error below 1 microarcsecond over 1980-2020)::

dψ sin ε₀= dX
dε = dY

or the accurate relation, written in the chapter 5 of the IERS 2000 conventions, of which the programmation is proposed here (see uai package 2000).