Auto-negotiation and link training in 10GBASE-R standards family
-LR, -SR, and -ER are all just -R.  The only difference between -LR, -SR, -ER, and direct attach copper is the medium in between the SFP+ modules.  Direct attach copper is just a copper wire, -SR is multi-mode fiber with 850 nm VCSELs, -LR is single mode fiber with 1310 nm lasers, -ER is single mode fiber with 1550 nm lasers.  All of these send raw 64b/66b encoded data without link auto-negotiation or link training.  

-KR is special in that it has extra auto-negotiation features.  

Source: IEEE 802.3-2008, section 4.