Single Quote use in cell reference

[Eric]

I am trying to decifer a spreadsheet prepared by someone who has left the
company. They used the following cell reference, which appears to reference
an outside spreadsheet without using the full spreadsheet name, ='AR
''06'!G414.

What do the two separate items in single quotes do. I can't figure out what
'AR ''06' is?

Any thoughts are greatly appreciated.

Thank You,

 

[Reitanos]

Excel uses the single quotes around a sheet name that includes spaces,
but because the author of the document named the sheet AR '06 (using
the apostrophe to indicate the missing 20 from 2006) Excel had to add
the second apostrophe.