Unless something has changed in the past few years, here is a pertinent thread on Web Special Awards. This thread may get merged into that, unless someone can point to situations that prove otherwise.
"Economy Web Special" Award (dynamic price, fewer miles, more restrictions Oct 2018)
Economy Web Special awards
Economy Web Special awards are available exclusively on aa.com and may be offered on select flights and dates for fewer miles than either the MileSAAver or AAnytime award level. Travel is in the Main Cabin, and mileage levels vary by date and flight. When available, you’ll see the applicable award level while booking your trip. Tickets that include an Economy Web Special award don’t allow changes and, while you can cancel and reinstate your miles, fees may apply.
(bolding/red font mine to make that part stand out)