I was wondering why do you have to name the subtitles track the same as the movie file?
And what if you want subtitles in multiple languages like English and Spanish?
[This is a little off topic, but seeing as there are 75 other Q's with the subtitle tag...]
I'm assuming you're referring to softsubs, where you'll have
The name of the subtiles file doesn't need to be the same as that of the movie. However, many popular video players will automatically look for subtitle files which share the same name as the video file and automatically load them. Otherwise you must load the files manually. For example, in VLC Player when you open a movie you can specify a subtitle file by going Video --> Subtitles Track --> Open File....
As you can guess, this is what you need to do if you have subtitle files for multiple languages.
Another alternative to having to manage all these subtitle files is to use a different container format. An AVI file is the most basic media container. It contains up to 1 video stream, and up to 1 audio stream. OGM supports up to 1 video stream, multiple audio streams, and multiple subtitles (I believe... I don't use OGM much anymore). MKV supports multiple video, multiple audio, and multiple subtitles.