I was also wondering if there was a list of scholarship messages and their interpretations, but I ran a search and this is all I could find. So I thought I'd try my hand at starting one. Feel free to chime in if you think I'm misinterpreting something, or if you have other messages to add.
1. If I had to give you an answer now, I'd say no, but I just can't decide. Okay, so this one is kinda obvious. Behind.
1A. The offer is great, but I don't know enough about you or your program to say yes right now. Got this one when another team jumped on the consideration list and I didn't. So definitely behind.
1B. Thanks for the offer. I like your program, but I need more information before I can say yes or no. Got this after #6 without any more effort, so if that was even or slightly ahead, this must be behind
2. You've said everything I needed to hear, can't wait to sign! Also obvious. Ahead.
2A. If nothing changes, you've got yourself a player. Putting the obvious ones together. Also ahead
2B. You've sold me. If nothing changes. Also ahead
3. I'm on the fence right now. There are a couple other schools I really like too. I can't decide.
This message appeared when no one else was on his considering list, so I think it means slightly ahead I had misread my notes. This means you're behind.
3A. You've said everything I need to hear, but so has another school. I can see myself playing for you, but I just can't decide. I might be making a mistake grouping this with message #3, but since it was the last message I received before the guy signed (and when I was the only one being considered), it definitely means slightly ahead
4. I'd be honored to play for you, but I'd be honored to play for a couple other schools too. I just need more time. This message appeared after I'd had a #2-style message and been the only person considered. When this message appeared, others joined the consideration list. So it either means I've gone from way ahead to slightly ahead, to slightly behind, or to even. I'm guessing even. This, however, was just a guess. Tianyi is much more experienced than me, and he says behind.
5. Can't say yes or no right now. I'm about to visit campus of another school. I'd like to learn more about your school though. This was the last message I received before I eventually dropped off his consideration list, so I'm guessing it means solidly behind
6. I'm really struggling, you have a nice program and your school is great, but it's such a big decision. I need more time. Got this after I popped onto the consideration list alongside another school. So it means not solidly behind anymore. Not sure if it's slightly behind, slightly ahead, or even. Guessing even. Again, a guess, and tianyi says behind. Presumably very slightly behind.
7. You have a little more selling to do. Don't get me wrong, you're close, but other schools have indicated possible interest. Got this after #1B and one more home visit. So if that was behind, this means it's close. Even? Slightly ahead? My guess is even. Again, a guess, again, tianyi says slightly behind. Apparently tianyi doesn't believe in any "even" messages. Update: I recently got this message after I had put effort in but the recruit was not considering anyone. It took five phone calls and five letters to move from this message to a #11 message, which I interpret as clearly ahead. I'm not sure what would've happened if I hadn't sent any letters, but I think it's clear that no one else was in this battle, and if it's not ahead, it's so close to ahead that extremely minimal effort will move it into ahead.
8. I love your program, but I need to give each school my full attention. Got this after getting message #7 and sending another HV. So if that was even, this is probably slightly ahead. After one more visit, I was into 2B territory
9. I can't say yes right now. I'm supposed to visit the campus of another school. I should know more after that. On the surface, this looks a lot like #5, which would indicate being behind, but I don't think it's quite the same. First of all, I got this message just one cycle after a #2-type message, and I only needed one HV to push it back into #2-type territory. I think, despite similarities in form, #5 says "I'd like to know more about you," and this says "I'm learning more about them." So #5 is a warning that you're behind but have a chance to catch up. I think this is a warning that you're slightly ahead but someone else is closing fast. From darnoc's comments, I amend my guess to slightly behind. It has to be slight either way if only one HV changes it to #2, but if you get it before somebody signs elsewhere, I guess it's behind. Chichisteve confirms behind
10. Thanks for the offer. I really like your program, but I have other options I want to check out. I have no idea what to think about this one. I received it a couple cycles after a #2-style message, and it took three visits over three cycles to get into a #11-style message, but there were no intervening messages saying I'd gone from slightly behind to even. So maybe this is another slightly ahead? An even? A slightly behind? I just don't know. Hawkfan says he received this message a cycle before a target signed elsewhere, so behind.
11. I'm struggling. Your school and program is fantastic, but it's such a big decision. I'm very close to making my decision though. I suspect that this is as far ahead as you can be during the signing period without getting them to sign. It looks like a strong message, and it came after I'd put in three HVs after #10. After a couple cycles of not giving any more HVs, I dropped to a #6-style message. So if that's even, this must be ahead
12. You offer means a lot to me. I could see myself there next year, but another school is offering me to make a name for myself, and that's really appealing. I just need more time. Got this message right before the 8AM cycle on the last day. I won on the 8 AM cycle of the last day. So I guess this must be slightly ahead
13. You're on my very short list, but I still need more information. In the past, I had gotten this message, and one more HV got me into 3A territory. So if I've categorized 3A correctly, this message must mean it's very, very close. However, today I got this message from a recruit who signed elsewhere the next cycle. So it must be behind. I'm guessing slightly behind.
14. You're on my very short list. I can't say yes until I've made my final campus visits, but as it stands right now, you're my top choice. Obvious ahead message is obvious.
15. I really love your program, but I need to give each program my full attention before I make my decision. I can't say yes right now. Sorry. This looks a lot like #8, and I don't remember what caused me to say #8 was slightly ahead, but I recently received this message and WOTS confirmed that I was slightly behind.