(used to imply that either or both of the things mentioned may be affected or involved): insurance covering fire and/or wind damage.
The combination and/or is used primarily in business and legal writing: All dwellings and/or other structures on the property are included in the contract. Because of these business and legal associations, some object to the use of this combination in general writing, where it occasionally occurs: She spends much of her leisure time entertaining and/or traveling. In such writing, either and or or is usually adequate. If a greater distinction is needed, another phrasing is available: Would you like cream or sugar, or both?
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(coordinating) used to join terms when either one or the other or both is indicatedpassports and/or other means of identification
Many people think that and/or is only acceptable in legal and commercial contexts. In other contexts, it is better to use or both: some alcoholics lose their jobs or their driving licences or both (not their jobs and/or their driving licences)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Both or either of two options. For example, His use of copyrighted material shows that the writer is careless and/or dishonest. This idiom originated in legal terminology of the mid-1800s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.