Use quotation marks to search for an "exact phrase". Append an asterisk (*) to a search term to find variations of it (transp*, 32019R*). Use a question mark (?) instead of a single character in your search term to find variations of it (ca?e finds case, cane, care).
Query: (PS_ID="dir:2017:541:corrigendum:2018-04-09:oj" OR (DTN_ELI=541 AND DTA=2017 AND FM_CODED=DIR OR DIR_DEL OR DIR_IMPL AND DTC=false)) NOT ELI = NULL, Search language: English