This is "fzn-oscar-cbls", a MiniZinc backend using the Oscar/CBLS solver. It solves problems by using constraint-based local search in an adapative tabu search setting. Before running the search, the backend looks for one-way constraints that can be implemented by invariants and for implicit constraints that can be maintained during search through specific neighbourhoods. During search the backend performs propagation, using some parts of OscaR/CP, to reduce the size of the search space. This backend has been described more in depth in [BMFP15] and has been first developed as part of Gustav Björdal's bachelor thesis [Bjö14]. More info on OscaR can be found at http://www.oscarlib.org. The CBLS engine of OscaR is developed at CETIC, Belgium, by Renaud De Landtsheer, Yoann Guyot, and Gustavo Ospina. OscaR is free software and distributed under the terms of the LGPL v2.1. This entry to the MiniZinc Challenge 2018 is submitted by: Gustav Björdal (Uppsala University, Sweden) Jean-Noël Monette (Tacton Systems AB, Sweden) Pierre Flener (Uppsala University, Sweden) Justin Pearson (Uppsala University, Sweden) http://www.it.uu.se/research/group/astra/ and Renaud De Landtsheer (CETIC research centre, Belgium) Yoann Guyot (CETIC research centre, Belgium) Gustavo Ospina (CETIC research centre, Belgium) https://www.cetic.be/ [BMFP15] G. Björdal, J.-N. Monette, P. Flener, and J. Pearson. A constraint-based local search backend for MiniZinc. Constraints, journal fast track of CP-AI-OR 2015, 20(3):325-345, July 2015. (http://dx.doi.org/10.1007/s10601-015-9184-z) [Bjö14] G. Björdal: The First Constraint-Based Local Search Backend for MiniZinc. Bachelor Thesis in Computer Science, Report IT 14 066, Faculty of Science and Technology. Uppsala University, Sweden, 2014. (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-234847)