[anthony-wohali]

In the ASME is written :
(-b) The depth of the flaw shall be drawn normal to the inside pressure retaining surface and shall be denoted as “a” for a surface flaw or “2a” for a subsurface flaw.

For me denoted means it is written as “a” for surface flaws and written as 2a for subsurface flaws.
So it is not allowed to take 2 time a for subsurface flaws. it is just written this way