about ''float4 uv[8] : TEXCOORD0;'' Solved!!!!

There is one statement in a vertex shader implementation I found in a research talk like this:

float4 uv[8] : TEXCOORD0;

how can it save an array into one texel?
When I write this statement in Nvidia Cg, an error pops up saying “output semantic attribute “TEXCOORD” has too big of a numeric index”, how can I solve that?

in my implementation, I begin with TEXCOORD1, so I can only access to uv[7]. Now I revised it to TEXCOORD0, and I am able to access to uv[8].

Although I do not know the theory behind it.