but it looks like it could be useful for naming an array entry (Recipe7.Name = "Fried Chicken Suckers").
Sadly, no. A STRING is a structure, along with User Data Types. But Do-more does not support nested structures.
What you are seeing is a way to format a numeric DWORD or WORD or BYTE's DEFAULT DISPLAY format. Normally, it's 2's complement decimal integer. But you may want to look at in HEXADECIMAL or even OCTAL. We also have ASCII/SWAPPED ASCII. So, if you had a DWORD that is 4 BYTEs long, you could look at it as ASCII if that came from the source that way (think of a Modbus Holding Register that contained text, e.g. 0x44434241 would be "ABCD" ASCII or "DCBA" SWAPPED ASCII (I may have those backwards)).
I guess you could technically stick a bunch of DWORD members in a structure to make up a name (e.g. 4 DWORDs called .Name1, .Name2, .Name3, .Name4 for up to 16 character name), but that really isn't a "string" or even particularly useful.
One way around this would be to have two data-blocks - a block called RecipeName, and another block called Recipe, and the ID/Index of the two blocks correspond to each other, so RecipeName7 would be "Fried Chicken Suckers", but Recipe7.CookTime Recipe7.CookTemp would be two fields in the Recipe7 structure of the Recipe block.