VALD does not guarantee in any way the absence of errors in the original data, but we are very interested in reducing their number. Therefore we encourage VALD users to send us error reports, so that we can notify other users and attempt to correct the data. Please send your messages to the VALD administrator via e-mail (valdadm@galileo.ast.univie.ac.at) or with a regular mail to the address given below. If data is used for spectroscopic analysis one needs to know about the reliability of the source. The gf-values have to be used with special care. Some of the sources contain data compilations which are updated from time to time without prior warning by their authors (e.g. the BELL lists). There is therefore no way to maintain a quality estimate for EACH individual line in these lists. In addition, some lists (e.g. GFIRON) consist of semiempirically calculated gf-values with a primary focus on completeness of the list rather than the highest possible accuracy. The VALD team will compile a special list for known "wrong" lines. We will enable this compilation to be taken into account for data extraction, too.