Fit Symbols for holes and cylinders

I am new to SolidWorks and am going through some tutorials.  In one of the tutorials for a tic tac toe game, the holes in the block are a fitting of D10 (Ø8D10) and the pegs have a shaft fit of h9 (Ø8h9).  What does the D10 and h9 designation mean?  Does anyone know of a reference?

Thanks

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