diff --git a/Source/Core/Core/PowerPC/PPCTables.h b/Source/Core/Core/PowerPC/PPCTables.h
index ea6c2ac978..3384f7f63f 100644
--- a/Source/Core/Core/PowerPC/PPCTables.h
+++ b/Source/Core/Core/PowerPC/PPCTables.h
@@ -7,50 +7,51 @@
 #include "Core/PowerPC/Gekko.h"
 #include "Core/PowerPC/Interpreter/Interpreter.h"
 
+// Flags that indicate what an instruction can do.
 enum
 {
-	FL_SET_CR0         = (1<<0), //
-	FL_SET_CR1         = (1<<1), //
-	FL_SET_CRn         = (1<<2), //
-	FL_SET_CRx         = FL_SET_CR0 | FL_SET_CR1 | FL_SET_CRn, //
-	FL_SET_CA          = (1<<3), // carry
-	FL_READ_CA         = (1<<4), // carry
-	FL_RC_BIT          = (1<<5),
-	FL_RC_BIT_F        = (1<<6),
-	FL_ENDBLOCK        = (1<<7),
-	FL_IN_A            = (1<<8),
-	FL_IN_A0           = (1<<9),
-	FL_IN_B            = (1<<10),
-	FL_IN_C            = (1<<11),
-	FL_IN_S            = (1<<12),
+	FL_SET_CR0         = (1<<0),  // Sets CR0.
+	FL_SET_CR1         = (1<<1),  // Sets CR1.
+	FL_SET_CRn         = (1<<2),  // Encoding decides which CR can be set.
+	FL_SET_CRx         = FL_SET_CR0 | FL_SET_CR1 | FL_SET_CRn,
+	FL_SET_CA          = (1<<3),  // Sets the carry flag.
+	FL_READ_CA         = (1<<4),  // Reads the carry flag.
+	FL_RC_BIT          = (1<<5),  // Sets the record bit.
+	FL_RC_BIT_F        = (1<<6),  // Sets the record bit. Used for floatig point instructions that do this.
+	FL_ENDBLOCK        = (1<<7),  // Specifies the end of a JIT block.
+	FL_IN_A            = (1<<8),  // Uses rA as an input.
+	FL_IN_A0           = (1<<9),  // Uses rA as an input. Indicates when rA is used with an instruction, it's treated as if it has the value zero in it.
+	FL_IN_B            = (1<<10), // Uses rB as an input.
+	FL_IN_C            = (1<<11), // Uses rC as an input.
+	FL_IN_S            = (1<<12), // Uses rS as an input.
 	FL_IN_AB           = FL_IN_A | FL_IN_B,
 	FL_IN_AC           = FL_IN_A | FL_IN_C,
 	FL_IN_ABC          = FL_IN_A | FL_IN_B | FL_IN_C,
 	FL_IN_SB           = FL_IN_S | FL_IN_B,
 	FL_IN_A0B          = FL_IN_A0 | FL_IN_B,
 	FL_IN_A0BC         = FL_IN_A0 | FL_IN_B | FL_IN_C,
-	FL_OUT_D           = (1<<13),
-	FL_OUT_S           = FL_OUT_D,
-	FL_OUT_A           = (1<<14),
+	FL_OUT_D           = (1<<13),  // rD is used as a destination.
+	FL_OUT_S           = FL_OUT_D, // rS is used as a destination.
+	FL_OUT_A           = (1<<14),  // rA is used as a destination.
 	FL_OUT_AD          = FL_OUT_A | FL_OUT_D,
-	FL_TIMER           = (1<<15),
-	FL_CHECKEXCEPTIONS = (1<<16),
-	FL_EVIL            = (1<<17),
-	FL_USE_FPU         = (1<<18),
-	FL_LOADSTORE       = (1<<19),
-	FL_SET_FPRF        = (1<<20),
-	FL_READ_FPRF       = (1<<21),
-	FL_SET_OE          = (1<<22),
-	FL_IN_FLOAT_A      = (1<<23),
-	FL_IN_FLOAT_B      = (1<<24),
-	FL_IN_FLOAT_C      = (1<<25),
-	FL_IN_FLOAT_S      = (1<<26),
-	FL_IN_FLOAT_D      = (1<<27),
+	FL_TIMER           = (1<<15),  // Used only for mftb.
+	FL_CHECKEXCEPTIONS = (1<<16),  // Used with rfi/rfid.
+	FL_EVIL            = (1<<17),  // Historically used to refer to instructions that messed up Super Monkey Ball.
+	FL_USE_FPU         = (1<<18),  // Used to indicate a floating point instruction.
+	FL_LOADSTORE       = (1<<19),  // Used to indicate a load/store instruction.
+	FL_SET_FPRF        = (1<<20),  // Sets bits in the FPRF.
+	FL_READ_FPRF       = (1<<21),  // Reads bits from the FPRF.
+	FL_SET_OE          = (1<<22),  // Sets the overflow flag.
+	FL_IN_FLOAT_A      = (1<<23),  // frA is used as an input.
+	FL_IN_FLOAT_B      = (1<<24),  // frB is used as an input.
+	FL_IN_FLOAT_C      = (1<<25),  // frC is used as an input.
+	FL_IN_FLOAT_S      = (1<<26),  // frS is used as an input.
+	FL_IN_FLOAT_D      = (1<<27),  // frD is used as an input.
 	FL_IN_FLOAT_AB     = FL_IN_FLOAT_A | FL_IN_FLOAT_B,
 	FL_IN_FLOAT_AC     = FL_IN_FLOAT_A | FL_IN_FLOAT_C,
 	FL_IN_FLOAT_ABC    = FL_IN_FLOAT_A | FL_IN_FLOAT_B | FL_IN_FLOAT_C,
-	FL_OUT_FLOAT_D     = (1<<28),
-	FL_OUT_FLOAT_S     = (1<<29),
+	FL_OUT_FLOAT_D     = (1<<28),  // frD is used as a destination.
+	FL_OUT_FLOAT_S     = (1<<29),  // frS is used as a destination.
 	// Used in the case of double ops (they don't modify the top half of the output)
 	FL_INOUT_FLOAT_D   = FL_IN_FLOAT_D | FL_OUT_FLOAT_D,
 };