I am dynamically Emitting a switch statement using System.Reflection.Emit.
I have used the ILDASM and copied a switch statement’s syntax as a reference.  I run my code to build the function and I got an Illegal One-Byte branch exception.  I figured out that the first couple of (break;) jumps use Br and the rest use Br_S.  I then wrote another switch function example with a different number of cases and looked at the IL code.  It uses a different number of Br statements at the beginning before using Br_S for the rest of the (break;) jumps.  There is no good documentation on the difference between short form and normal form.  

How do you know if you are supposed to use Br or Br_S?

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ILCODE EXAMPLE ONE
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IL_0111:  switch     (
                       IL_014b,
                       IL_015c,
                       IL_016a,
                       IL_0178,
                       IL_0186,
                       IL_0194,
                       IL_01a2,
                       IL_01ab,
                       IL_01b4,
                       IL_01bd,
                       IL_01c6,
                       IL_01cf)
 IL_0146:  br         IL_01d8
 IL_014b:  ldarg.0
 IL_014c:  ldfld      int32 [Northwind]Northwind.Order::orderId
 IL_0151:  box        [mscorlib]System.Int32
 IL_0156:  stloc.0
 IL_0157:  br         IL_01de
 IL_015c:  ldarg.0
 IL_015d:  ldfld      valuetype [mscorlib]System.DateTime [Northwind]Northwind.Order::orderDate
 IL_0162:  box        [mscorlib]System.DateTime
 IL_0167:  stloc.0
 IL_0168:  br.s       IL_01de
 IL_016a:  ldarg.0
 IL_016b:  ldfld      valuetype [mscorlib]System.DateTime [Northwind]Northwind.Order::requiredDate
 IL_0170:  box        [mscorlib]System.DateTime
 IL_0175:  stloc.0
 IL_0176:  br.s       IL_01de

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ILCODE EXAMPLE TWO
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IL_016b:  switch     (
                       IL_01b9,
                       IL_01ca,
                       IL_01d6,
                       IL_01e2,
                       IL_01ee,
                       IL_01fa,
                       IL_0208,
                       IL_0216,
                       IL_021f,
                       IL_0228,
                       IL_0231,
                       IL_023a,
                       IL_0243,
                       IL_024c,
                       IL_0255,
                       IL_025e,
                       IL_026c)
 IL_01b4:  br         IL_0275
 IL_01b9:  ldarg.0
 IL_01ba:  ldfld      int32 [Northwind]Northwind.Employee::employeeId
 IL_01bf:  box        [mscorlib]System.Int32
 IL_01c4:  stloc.0
 IL_01c5:  br         IL_027b
 IL_01ca:  ldarg.0
 IL_01cb:  call       instance string [Northwind]Northwind.Employee::get_FirstName()
 IL_01d0:  stloc.0
 IL_01d1:  br         IL_027b
 IL_01d6:  ldarg.0
 IL_01d7:  call       instance string [Northwind]Northwind.Employee::get_LastName()
 IL_01dc:  stloc.0
 IL_01dd:  br         IL_027b
 IL_01e2:  ldarg.0
 IL_01e3:  call       instance string [Northwind]Northwind.Employee::get_Title()
 IL_01e8:  stloc.0
 IL_01e9:  br         IL_027b
 IL_01ee:  ldarg.0
 IL_01ef:  call       instance string [Northwind]Northwind.Employee::get_TitleOfCourtesy()
 IL_01f4:  stloc.0
 IL_01f5:  br         IL_027b
 IL_01fa:  ldarg.0
 IL_01fb:  call       instance valuetype [mscorlib]System.DateTime [Northwind]Northwind.Employee::get_BirthDate()
 IL_0200:  box        [mscorlib]System.DateTime
 IL_0205:  stloc.0
 IL_0206:  br.s       IL_027b
 IL_0208:  ldarg.0
 IL_0209:  call       instance valuetype [mscorlib]System.DateTime [Northwind]Northwind.Employee::get_HireDate()
 IL_020e:  box        [mscorlib]System.DateTime
 IL_0213:  stloc.0
 IL_0214:  br.s       IL_027b