Accounting Question

[SlowHabit]

I was reading an annual report and am not sure what this means:

"At June 30, 2007, the Company had a total of $540,000 of long-term revolving credit facilities under the 2005 Senior Credit Facility, which was comprised of the $490,000 Domestic Revolver and the $50,000 Foreign Revolver (collectively, the Revolvers). The Revolvers provide for the issuance of letters of credit which, when issued, constitute usage and reduce availability under the Revolvers. The aggregate amount of letters of credit outstanding under the Revolvers was $68,479 at June 30, 2007. After giving effect to letters of credit, $324,000 in borrowings under the Domestic Revolver and $16,631 in borrowings under the Foreign Revolver, total availability under the Revolvers was $130,890 at June 30, 2007."

Fortunately, I have a calculator and did some arithmetic and have the following summary. Company A has a credit line of $540,000 under the 2005 Senior Credit Facility plan. In this plan, $490,000 is used for domestic operation and $50,000 is used for foreign operation. As of June 30th, 2007, the domestic operation has borrowed $324,000 and the foreign operation has borrowed $16,631. Other use of credit amount to $68,479. Company A now have a credit line of $130,890.

AMIRITE?

PS. I am confused because I do not understand what "the aggregate amount of letters of credit outstanding under the Revolvers was $68,479 at June 30, 2007 means.