You can define characters or words that will be ignored when the user performs a product search.
When dashes or other special characters exist in SKU numbers or in any other field, it is beneficial to omit them in the search query
By default, two characters are set to be ignored: – and _
When your product SKU number is 01_ROS_2017, the user must insert the dashes to find this particular product. If you have configured the search to ignore the dashes, you will find this product with 01 ROS 2017 (the same but without the dashes).