Exclude "ContentLink Id" of variant or product type from search

Currently when user search with number and if that matches with "ContentLink Id" of catalog variant/product then that variant/product get returned as a search result. How can I avoid that "ContentLink Id" is being searched from my query?

Below is my sample query used to get products - 

query
.For(searchText)
.WithAndAsDefaultOperator()
.UsingSynonyms()
.FilterOnProductCategory(categoryLink)
public static ITypeSearch<T> FilterOnProductCategory<T>(this ITypeSearch<T> query, ContentReference categoryLink) where T : IProductVariant
{
	if (categoryLink.IsNullOrEmpty())
	{
		return query;
	}
	return query.Filter(x => x.ParentNodeRelationIdsRecursive().Match(categoryLink.ToString()));
}

Note - Find version I am using : 13.2.6.0

Thanks in advance.