The PROMOTE Stratospheric Ozone Profile Record service has been setup to deliver 3D global re-analyses of ozone and other related trace gases (www.gse-promote.org). Provided by DLR and BIRA-IASB, re-analyses will cover the period from 1992 until now. Both institutions are running their own assimilation system dealing with different datasets, thus covering different time periods. DLR is focusing on GOME-1 (1995-2003), MIPAS (July 2002-March 2004) and GOME-2 (2007-today) while BIRA-IASB is dealing with UARS/MLS (1992-1999) and MIPAS. At BIRA-IASB, analyses are calculated using the Belgian Assimilation System for Chemical ObsErvations (BASCOE). Like SACADA (Synoptic Analysis of Chemical constituents by Advanced Data Assimilation) applied at DLR, it is based on the 4D-Var method and a stratospheric Chemistry-Transport Model (CTM) driven by ECMWF meteorological analyses. In this contribution, we shall review the BASCOE target species of this PROMOTE service, i.e., ozone and total chlorine (Cly) analyses.