Just to add a minor clarification. I was not messing with string types, I would not dream of redefining a system-defined data type. The confusion over string types arose because, inadvertently, the H+ option became ineffective in my form units. That led to a conflict in the definition of OnMarkToText parameters, and an access error, not actually during the Create for the form, but in the call to OnMarkText when the chart was created.
I do always explicitly specify shortstring when that is what I want. I never use "string", partly because the string variables I need to define myself are, so far, well enough handled as shortstring, and partly because ambiguity in meaning of definitions makes me nervous.