Dimension Symbol Meaning?

[medemab]

Can anyone tell me what the "L" shapped symbols in the attached drawing view means? The "L" in the upper dimension extends along the left and bottom, the "L" in the lower dimension extends along the left and top. This is on a component spec which we are trying to call out the rectangular hole size for. I looked in a old version ASME Y14.5 standard, a older GD&T standard, and the internet, but did not find any symbols like this. Is this symbol even legitimate? Any help would be appreciated.
Thanks, medemab

 

[Rjeffery]

I think it is just a "container" for the dimentional tollerances

 

[CountOlaf]

Yeah...I agree with Rj...it looks like a bracket...a version of { or [ or you get the idea.