After using the SPAN method of the richtext control you won’t be able to set the VISIBLE property to false. I use this feature a lot. It is listed as a BUG in Microsoft article ID# Q189483 in the knowledge base.
Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear. TechnologyAdvice does not include all companies or all types of products available in the marketplace.