TITLE: GCN CIRCULAR NUMBER: 26324 SUBJECT: GRB 191004A: correction to reported GROND upper limits DATE: 19/12/02 22:48:59 GMT FROM: Patricia Schady at Swift P. Schady (Univ. of Bath) reports: I would like to correct a mistake in the GROND g'r'i'z' upper limits reported in Schady et al. (GCN #25959). The reported afterglow position (Osborne et al., GCN #25950; Lipunov et al., GCN #25944) lay at the edge of the g'r'i'z' field of view, where the exposure coverage is not complete. Taking into account the exposure map reduces the optical band 3 sigma upper limits reported in GCN #25959 by around 0.5 mag. The correct 3 sigma upper limits (AB system) are as follows: g’ > 23.3 r’ > 23.7 i’ > 23.1 z’ > 22.7 I would like to thank Jochen Greiner for bringing this mistake to my attention.