What does "N" do in a WHERE clause?

Hey all,

Getting used to a new Oracle 10.1.0.5.0 environment and am finding new and fun things every day. The latest I found is a SELECT statement, generated by Crystal Enterprise 10 if it matters, that has an odd syntax that I haven't seen before. Here's a snip:

WHERE NOT( MYTAB"."SDLNTY" = N'F'

              OR "MYTAB"."SDLNTY" = N'NS' )
AND      "MYTAB"."SDNXTR" < N'999'
AND      "MYTAB"."SDECST" = 0

The part that caught my eye in this loosely veiled query piece is the "N" modifier, or whatever it is. It doesn't look like a function, but it seems to be acting like CAST(). If it's important, the SQL is in ANSI syntax.

There's nothing that I could find browsing the SQL Reference doc and trying to Google "ANSI SQL N" didn't help, either. ;)

Anyone seen this before?

TIA!
Rich

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