ADA standards are set by the ADA act if you are in the US. Some or I think most states have taken over the enforcement of the ADA and so have their own requirements "that are at least" the standards set by the federal government. An individual state can impose stricter rules since their have taken ownership. So check with your state for the guidelines. For residential I bet they will not be too much different than the federal requirements. As far as the symbol, if the manufacturer does not provide one, then you can designate the proper area and clearances and reference the product(s) to use. As a general rule, if you want the bathroom to be ADA compliant, then you probably need to specify clearances to all fixtures, doors, etc.