This excerpt taken from the DLTR 10-K filed Apr 14, 2005.
Cash and Cash Equivalents
Cash and cash equivalents at January 29, 2005 and January 31, 2004 includes $75,885 and $54,081, respectively, of investments in money market securities and bank participation agreements which are valued at cost, which approximates market. The underlying assets of these short-term participation agreements are primarily commercial notes. For purposes of the consolidated statements of cash flows, the Company considers all highly liquid debt instruments with original maturities of three months or less to be cash equivalents.