diff --git a/src/bookkeeper.jl b/src/bookkeeper.jl
index a64e374..f0ef355 100644
--- a/src/bookkeeper.jl
+++ b/src/bookkeeper.jl
@@ -399,7 +399,7 @@ end
 function elegroup_bookkeeper!(ele::Ele, group::Type{BMultipoleParams}, changed::ChangedLedger, previous_ele::Ele)
   bmg = ele.BMultipoleParams
   cdict = ele.changed
-  if !has_changed(ele, BMultipoleParams) && !changed.this_ele_length && !changed.ref_group; return; end
+  if !has_changed(ele, BMultipoleParams) && !changed.this_ele_length && !changed.reference; return; end
 
   ff = ele.pc_ref / (C_LIGHT * charge(ele.species_ref))
 
@@ -434,7 +434,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{BMultipoleParams}, changed::
     end
 
     # Update multipoles if the reference energy has changed.
-    if changed.ref_group
+    if changed.reference
       if ele.field_master
         for mul in bmg.pole
           mul.Kn = mul.Bn / ff
@@ -461,7 +461,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{BendParams}, changed::Change
   bg = ele.BendParams
   cdict = ele.changed
 
-  if !has_changed(ele, BendParams) && !changed.this_ele_length && !changed.ref_group; return; end
+  if !has_changed(ele, BendParams) && !changed.this_ele_length && !changed.reference; return; end
 
   if ele.slave_status == Slave.SUPER
     lord = ele.super_lords[1]
@@ -633,7 +633,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{ReferenceParams}, changed::C
   drg = ele.DownstreamReferenceParams
   cdict = ele.changed
 
-  if has_changed(ele, ReferenceParams); changed.ref_group = true; end
+  if has_changed(ele, ReferenceParams); changed.reference = true; end
 
   if ele.slave_status == Slave.SUPER
     lord = ele.super_lords[1]
@@ -645,7 +645,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{ReferenceParams}, changed::C
   #
 
   if is_null(previous_ele)   # implies BeginningEle
-    if !changed.ref_group; return; end
+    if !changed.reference; return; end
     if rg.species_ref == Species(); error(f"Species not set for first element in branch: {ele_name(ele)}"); end
     drg.species_ref_downstream = rg.species_ref
 
@@ -676,7 +676,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{ReferenceParams}, changed::C
 
   # Propagate from previous ele
 
-  if !changed.this_ele_length && !changed.ref_group; return; end
+  if !changed.this_ele_length && !changed.reference; return; end
 
   old_drg = copy(drg)
 
@@ -710,7 +710,7 @@ function elegroup_bookkeeper!(ele::Ele, group::Type{ReferenceParams}, changed::C
   # End stuff
 
   clear_changed!(ele, ReferenceParams)
-  changed.ref_group = (old_drg != drg)
+  changed.reference = (old_drg != drg)
 
   return
 end
@@ -742,7 +742,7 @@ end
 function elegroup_bookkeeper!(ele::Ele, group::Type{SolenoidParams}, changed::ChangedLedger, previous_ele::Ele)
   sg = ele.SolenoidParams
   cdict = ele.changed
-  if !has_changed(ele, SolenoidParams) && !changed.ref_group; return; end
+  if !has_changed(ele, SolenoidParams) && !changed.reference; return; end
 
   ff = ele.pc_ref / (C_LIGHT * charge(ele.species_ref))
 
diff --git a/src/geometry.jl b/src/geometry.jl
index a495c5a..460a389 100644
--- a/src/geometry.jl
+++ b/src/geometry.jl
@@ -66,7 +66,7 @@ function coord_transform(ds::Number, g::Number, tilt_ref::Number = 0.0)
 
   else
     angle = ds/g
-    r_vec = [-ds * un_sinc(0.5*angle) * sin(angle), 0.0, ds * un_sinc(0.5*angle)]
+    r_vec = ds * [-angle * un_cosc, 0.0, un_sinc(angle)]
 
     qa = rotY(-angle)
     if tilt_ref == 0
diff --git a/src/parameters.jl b/src/parameters.jl
index 7cd4107..97ba440 100644
--- a/src/parameters.jl
+++ b/src/parameters.jl
@@ -85,6 +85,7 @@ ELE_PARAM_INFO_DICT = Dict(
   :super_lords        => ParamInfo(Nothing,        Vector{Ele},    "Array of element's super lords. Will not be present if no lords exist."),
   :slaves             => ParamInfo(Nothing,        Vector{Ele},    "Array of slaves of element. Will not be present if no slaves exist."),
   :girder             => ParamInfo(Nothing,        Ele,            "Supporting Girder element. Will not be present if no supporting girder."),
+  :from_forks         => ParamInfo(Nothing         Vector{Ele},    "List of fork elements that fork to this element."),
 
   :amp_function       => ParamInfo(ACKickerParams,  Function,       "Amplitude function."),
 
diff --git a/src/struct.jl b/src/struct.jl
index 6549916..01e1ed8 100644
--- a/src/struct.jl
+++ b/src/struct.jl
@@ -81,7 +81,7 @@ Element constructor Example:
     @ele q1 = Quadrupole(L = 0.2, Ks1 = 0.67, ...)
 Result: The variable `q1` is a `Quadrupole` with the argument values put the the appropriate place.
 
-Note: All element parameter groups associated with the element type will be constructed. Thus, in the
+Note: All element parameter structs associated with the element type will be constructed. Thus, in the
 above example,`q1` above will have `q1.LengthParams` (equivalent to `q1.pdict[:LengthParams]`) created.
 """
 macro ele(expr)
@@ -137,9 +137,9 @@ function (::Type{T})(; kwargs...) where T <: Ele
   pdict = ele.pdict
   pdict[:changed] = Dict{Union{Symbol,DataType},Any}()
 
-  # Setup parameter groups.
-  for group in PARAM_GROUPS_LIST[typeof(ele)]
-    pdict[Symbol(group)] = group()
+  # Setup parameter structs.
+  for struct in PARAM_GROUPS_LIST[typeof(ele)]
+    pdict[Symbol(struct)] = struct()
   end
 
   # Put name in first in case there are errors and the ele name needs to be printed.
@@ -149,7 +149,7 @@ function (::Type{T})(; kwargs...) where T <: Ele
     pdict[:name] = "Not Set!"
   end
 
-  # Put parameters in parameter groups and changed area
+  # Put parameters in parameter structs and changed area
   for (sym, val) in kwargs
     if sym == :name; continue; end
     Base.setproperty!(ele, sym, val)
@@ -254,13 +254,13 @@ end
 """
     Internal: struct EleParamsInfo
 
-Struct holding information on a single `EleParams` group.
+Struct holding information on a single `EleParams` struct.
 Used in constructing the `ELE_PARAM_GROUP_INFO` Dict.
 
 ## Contains
 • `description::String`      - Descriptive string. \\
 • `bookkeeping_needed::Bool  - If true, this indicates there exists a bookkeeping function for the \\
-  parameter group that needs to be called if a parameter of the group is changed. \\
+  parameter struct that needs to be called if a parameter of the struct is changed. \\
 """
 struct EleParamsInfo
   description::String
@@ -275,12 +275,12 @@ end
     abstract type EleParams <: BaseEleParams
     abstract type EleParameterSubParams <: BaseEleParams
 
-`EleParams` is the base type for all element parameter groups.
+`EleParams` is the base type for all element parameter structs.
 `EleParameterSubParams` is the base type for structs that are used as components of an element
-parameter group.
+parameter struct.
 
-To see in which element types contain a given parameter group, use the `info(::EleParams)`
-method. To see what parameter groups are contained in a Example:
+To see in which element types contain a given parameter struct, use the `info(::EleParams)`
+method. To see what parameter structs are contained in a Example:
 ```
     info(BodyShiftParams)      # List element types that contain BodyShiftParams
 ```
@@ -669,7 +669,7 @@ end
 """
     mutable struct DownstreamReferenceParams <: EleParams
 
-Downstream end of element reference energy and species. This group is useful for
+Downstream end of element reference energy and species. This struct is useful for
 elements where the reference energy or species is not constant.
 Elements where this is true include `LCavity`, `Foil`, and `Converter`.
 
@@ -825,7 +825,7 @@ end
     mutable struct OrientationParams <: EleParams
 
 Position and angular orientation.
-In a lattice element, this group gives the orientation at the entrance end of the element
+In a lattice element, this struct gives the Floor coordinates at the entrance end of the element
 ignoring alignment shifts.
 
 # Fields
@@ -1018,7 +1018,7 @@ end
 """
     mutable struct TwissParams <: EleParams
 
-Lattice element parameter group storing Twiss, dispersion and coupling parameters
+Lattice element parameter struct storing Twiss, dispersion and coupling parameters
 for an element.
 """ TwissParams
 
@@ -1035,10 +1035,10 @@ end
 """
     abstract type BaseOutput
 
-Abstract type from which output group structs inherit.
+Abstract type from which output parameter structs inherit.
 AcceleratorLattice defines `OutputParams <: BaseOutput` which is used for output parameters
 defined by AcceleratorLattice. Custom output parameters may be defined by defining a new 
-output group struct and a new `output_parameter` function method.
+output parameter struct and a new `output_parameter` function method.
 
 """
 abstract type BaseOutput end
@@ -1062,7 +1062,7 @@ end
     struct AllParams 
 
 Struct used for element parameter bookkeeping whose presence represents that parameters 
-in all parameter groups may have changed.
+in all parameter structs may have changed.
 """ AllParams
 
 struct AllParams; end
@@ -1202,7 +1202,7 @@ an element.
 # Fields
 • `this_ele_length::Bool`  - The length of the current element has changed. \\
 • `s_position::Bool`       - The longitudinal element position has changed. \\
-• `ref_group::Bool`        - Reference property (species, energy, or time) has changed. \\
+• `reference::Bool`        - Reference property (species, energy, or time) has changed. \\
 • `floor_position::Bool`   - The branch coordinate system has changed with respect to the floor coordinates. \\
 
 """ ChangedLedger
@@ -1210,6 +1210,6 @@ an element.
 @kwdef mutable struct ChangedLedger
   this_ele_length::Bool = false
   s_position::Bool = false
-  ref_group::Bool = false
+  refreference::Bool = false
   floor_position::Bool = false
 end
diff --git a/src/superimpose.jl b/src/superimpose.jl
index fd443b8..8c72228 100644
--- a/src/superimpose.jl
+++ b/src/superimpose.jl
@@ -288,7 +288,10 @@ function superimpose!(super_ele::Ele, ref::T; ele_origin::BodyLoc.T = BodyLoc.CE
 
   for lat in lat_list
     pop_bookkeeping_state!(lat)
-    if lat.autobookkeeping; bookkeeper!(lat); end
+    if lat.autobookkeeping
+      bookkeeper!(lat)
+      lat_sanity_check(lat)
+    end
   end
 
   return super_list
diff --git a/src/utilities.jl b/src/utilities.jl
index 6265fa4..fd55226 100644
--- a/src/utilities.jl
+++ b/src/utilities.jl
@@ -13,21 +13,87 @@ Does some self consistency checks on a lattice and throws an error if there is a
 
 function lat_sanity_check(lat::Lattice)
   for (ib, branch) in enumerate(lat.branch)
-    if ib != branch.ix_branch; error("SanityCheck: Branch with branch index: $ib has branch.ix_branch set to $(branch.ix_branch)"); end
-    if lat !== branch.lat; error("SanityCheck: Branch $ib has branch.lat not pointing to parient lat."); end
+    if ib != branch.ix_branch
+      error("SanityCheck: Branch with branch index: $ib has branch.ix_branch set to $(branch.ix_branch)")
+    end
+
+    if !(lat === branch.lat)
+      error("SanityCheck: Branch $ib has branch.lat not pointing to parient lat.")
+    end
 
     for (ie, ele) in enumerate(branch.ele)
+      pdict = ele.pdict
+
+
       if ie != ele.ix_ele; error("SanityCheck: Ele $(ele.name) in branch $ib with"*
                                       " element index: $ie has ele.ix_ele set to $(ele.ix_ele)"); end
 
-      if branch !== ele.branch; error("SanityCheck: Ele $(ele_name(ele)) has ele.branch not pointing to parient branch."); end
+      if !(branch === ele.branch)
+        error("SanityCheck: Ele $(ele_name(ele)) has ele.branch not pointing to parient branch.")
+      end
+
+      if branch.type == TrackingBranch && !haskey(pdict, :LengthParams)
+        error("Sanity check: Ele $(ele_name(ele)) does not have a LengthParams group.")
+      end
+      
+      if haskey(pdict, :girder)
+        lat_sanity_check(lat, ele, pdict[:girder], "girder")
+      end
+      
+      if haskey(pdict, :multipass_lord)
+        lat_sanity_check(lat, ele, pdict[:multipass_lord], "multipass lord")
+      end
+
+      if haskey(pdict, :ForkParams)
+        lat_sanity_check(lat, ele, pdict[:ForkParams].to_ele, "a forked-to element")
+      end
+
+      if haskey(pdict, :OriginEleParams)
+        lat_sanity_check(lat, ele, pdict[:OriginEleParams].origin_ele, "the element's origin element")
+      end
 
-      if branch.type == TrackingBranch
-        if !haskey(ele.pdict, :LengthParams) error("Sanity check: Ele $(ele_name(ele)) does not have a LengthParams group."); end
+      if haskey(pdict, :super_lords)
+        for lord in pdict[:super_lords]
+          lat_sanity_check(lat, ele, lord, "super lord")
+        end
       end
+
+      if haskey(pdict, :slaves)
+        for slave in pdict[:slaves]
+          lat_sanity_check(lat, ele, slave, "slave")
+        end
+      end
+
+      if haskey(pdict, :from_forks)
+        for fork in pdict[:from_forks]
+          lat_sanity_check(lat, ele, fork, "a fork that is forking to this element")
+        end
+      end
+
+      if haskey(pdict, :GirderParams)
+        for slave in pdict[:GirderParams].supported
+          lat_sanity_check(lat, ele, slave, "supported element")
+        end
+      end
+      
     end
   end
+end
+
+#-------------------
+# Internal lat_sanity_check method
+
+"""
+    Internal: 
 
+""" lat_sanity_check
+
+function lat_sanity_check(lat::Lattice, base_ele::Ele, pointed_ele::Ele, err_string::String)
+  pele = lat.branch[pele.branch.ix_branch].ele[pele.ix_ele]
+  if !(pointed_ele === pele)
+    error("Element $(ele_name(ele)) has a $err_string pointer to $(ele_name(pele)) but this\n" *
+          " pointed to element is in a different lattice!!!")
+  end
 end
 
 #---------------------------------------------------------------------------------------------------