What is a line?

Hi, I have been seeking membership into alpha kappa alpha for a while. The last line of individuals was in '06 and now I am practically almost a senior. I have attended all the functions, thus far and even the interest meetings. However, I have heard nothing about a new line coming up. This question is not pertaining to when they will have a line or what not. But all I am asking is how would you even know if one came about. We were never asked for information or anything. Could this just be rumors circulating, or could it actually be possible because things were held out in a secreative manner....So basically What is a line?