What are the current rules for adding players to "established" MLS rosters? Is there a trading deadline? I get the sense, that if a player's from your A-League affilate, you can almost add or drop him as needed. C'est vrai? What's the procedure for DC to acquire a Gaza or LA to that Korean national teamer? A "discovery" allocation? Did the Crewe "discover" Garcia? Did DC discover the El Salavadoran guy? What is Colorado's signing of Musa Shannon termed? Could an MLS team discover a Nelson Akawari or an Alex Yi right now, or do they have to wait until next year's draft?
Any use of the words "rules" and "MLS" in the same sentence is inherently suspect, but... At least as to the situation in LA, it is my understanding that LA was awarded an allocation as the result of the sale of Greg Vanney to Bastia. That allocation has not yet been used. The cutting of Winston Griffiths opens a roster slot. Can't comment on the other situations.
Shannon was picked up by the cRapids off the waiver list. DC have something called a Discovery Allocation they got from C-bus. (not sure how C-bus had this) As Cadaver said, LA have yet to replace Vanney (of course, they've yet to get compensation for Hersillemo or Hernandez...but that's another story)
I think your a bit off here at least on the DC/Cbus stuff. I know that Garcia was a discovery and I know that the Crew has one more "discovery" option available. From what I understand, (and this has been posted in the crew forums so I am giving it to you second or third hand) is that Cbus will wind up trading or dealing their discovery option to DC for a player. This will give DC the means they need to sign Gazza and Cbus probably some shite player in returnm with our luck. I still don't understand why the crew had all these discovery options or where they came from though.
The last date for waiving players was supposedly July 1. However, MLS Confidential reports that some players were told they'd be waived if they didn't sign an extension that set Sept 1 as the date their contracts would be guaranteed. MLS Confidential reports that more than a dozen players, including 4 Fire and 2 Galaxy players, were pressured into signing the extension.
First item in the MLS rule book: 1. All rules are subject to change. Half the time MLS can't figure out their rules so they make stuff up as they go.
I know, I know, MLS rules are very murky. But I have to say that Garber has been making progress in making the league more transparent. Maybe Jeff Bradley can address the current ways in which MLS player aquisition works in a midseason boot room or something.