EnergyModelsX · JulStraus · Apr 16, 2026 · Apr 16, 2026 · Apr 16, 2026 · Apr 16, 2026
diff --git a/NEWS.md b/NEWS.md
@@ -1,6 +1,6 @@
 # Release notes
 
-## Unversioned
+## Version 0.12.0 (2026-04-16)
 
 ### Breaking changes
 
@@ -11,6 +11,10 @@
 * Removed legacy constructors for `TransInvData` (you can see how to update existing models in *[the documentation of `EnergyModelsInvestments`](https://energymodelsx.github.io/EnergyModelsInvestments.jl/stable/how-to/update-models/#how_to-update-05-inv_data)).
 * Removed legacy constructors for `GeoAvailability`, `PipeSimple`, and `PipeLinepackSimple` (you can see how to update existing models in *[the documentation of `EnergyModelsGeography`](https://energymodelsx.github.io/EnergyModelsGeography.jl/stable/how-to/update-models/#how_to-update-09))
 
+### Minor updates
+
+* Adjustments to the documentation.
+
 ## Version 0.11.6 (2026-04-15)
 
 ### Add support for resource-specific constraint functions

diff --git a/docs/src/area_mode/area.md b/docs/src/area_mode/area.md
@@ -56,7 +56,7 @@ with square brackets, while functions are represented as
 
 ``func\_example(index_1, index_2)``
 
-with paranthesis.
+with parantheses.
 
 In addition, we simplify the description as:
 
@@ -167,7 +167,7 @@ with square brackets, while functions are represented as
 
 ``func\_example(index_1, index_2)``
 
-with paranthesis.
+with parantheses.
 
 #### [Variables](@id area_mode-areas-availability-math-var)
 

diff --git a/docs/src/area_mode/mode.md b/docs/src/area_mode/mode.md
@@ -58,7 +58,7 @@ The fields of the types are given as:
   The transmission loss is calculated as a ratio of the transported resource.
   It is an absolute ratio, *i.e.*, it is not dependent on the distance of the transmission corridor.
 - **`opex_var::TimeProfile`**:\
-  The variable operational expenses are based on the capacity utilization through the variable [`:trans_out`](@ref man-opt_var-transmission_mode).
+  The variable operating expenses are based on the capacity utilization through the variable [`:trans_out`](@ref man-opt_var-transmission_mode).
   Hence, it is directly related to the specified `output` ratios.
   The variable operating expenses can be provided as `OperationalProfile` as well.
 - **`opex_fixed::TimeProfile`**:\
@@ -97,7 +97,7 @@ with square brackets, while functions are represented as
 
 ``func\_example(index_1, index_2)``
 
-with paranthesis.
+with parantheses.
 
 ### [Variables](@id area_mode-trans_mode-math-var)
 

diff --git a/ext/EMIExt/EMIExt.jl b/ext/EMIExt/EMIExt.jl
@@ -40,7 +40,7 @@ EMI.get_var_inst(m, prefix::Symbol, tm::EMG.TransmissionMode)  = m[Symbol(prefix
     EMI.investment_data(tm::EMG.TransmissionMode, field::Symbol)
 
 Return the `InvestmentData` of the transmission mode `tm` or if `field` is specified, it
-returns the `InvData` for the corresponding capacity.
+returns the `InvestmentData` for the corresponding capacity.
 """
 EMI.investment_data(tm::EMG.TransmissionMode) =
     tm.data[findfirst(data -> typeof(data) <: InvestmentData, mode_data(tm))]

diff --git a/src/constraint_functions.jl b/src/constraint_functions.jl
@@ -53,9 +53,9 @@ end
 """
     constraints_capacity(m, tm::PipeLinepackSimple, 𝒯::TimeStructure, modeltype::EnergyModel)
 
-Function for creating the constraint on the maximum capacity of a [`PipeLinepackSimple`](@ref).
+Method for creating the constraint on the maximum capacity of a [`PipeLinepackSimple`](@ref).
 
-The difference is given by the inclusion of the linepack storage level constraint.
+The function introduces in addition an upper bound on the linepack storage level.
 """
 function constraints_capacity(m, tm::PipeLinepackSimple, 𝒯::TimeStructure, modeltype::EnergyModel)
 
@@ -157,7 +157,9 @@ end
 """
     constraints_trans_balance(m, tm::PipeLinepackSimple, 𝒯::TimeStructure, modeltype::EnergyModel)
 
-Function for creating the transmission balance for a [`PipeLinepackSimple`](@ref).
+Method for creating the transmission balance for a [`PipeLinepackSimple`](@ref).
+
+It adds the linepack level balance.
 """
 function constraints_trans_balance(m, tm::PipeLinepackSimple, 𝒯::TimeStructure, modeltype::EnergyModel)
 

diff --git a/src/model.jl b/src/model.jl
@@ -131,7 +131,7 @@ Declaration of different OPEX variables for the element types introduced in
 only `ℒᵗʳᵃⁿˢ::Vector{Transmission}` requires operational expense variables.
 
 !!! note "Transmission variables"
-    The operational expenses variables are only created for [`TransmissionMode`](@ref)s and
+    The operating expenses variables are only created for [`TransmissionMode`](@ref)s and
     not [`Transmission`](@ref) corridors. The OPEX variables are furthermore only created
     for nodes, if the function [`has_opex(tm::TransmissionMode)`](@ref) has received an
     additional method for a given mode `m` returning the value `true`. By default, this
@@ -161,8 +161,13 @@ function EMB.variables_opex(m, 𝒜::Vector{<:Area}, 𝒳ᵛᵉᶜ, 𝒯, modelt
     EMB.variables_capex(m, ℒᵗʳᵃⁿˢ::Vector{Transmission}, 𝒳ᵛᵉᶜ, 𝒯, modeltype::EnergyModel)
     EMB.variables_capex(m, 𝒜::Vector{<:Area}, 𝒳ᵛᵉᶜ, 𝒯, modeltype::EnergyModel)
 
-Create variables for the capital costs for the investments in transmission.
-Empty function to allow for multiple dispatch in the `EnergyModelsInvestment` package.
+
+Declaration of different capital expenditures variables for the element types introduced in
+`EnergyModelsGeography`. `EnergyModelsGeography` introduces two elements for an energy
+system, and hence, provides the user with two individual methods.
+
+!!! note
+    The function is included for legacy support but will be removed in the near future.
 """
 function EMB.variables_capex(m, ℒᵗʳᵃⁿˢ::Vector{Transmission}, 𝒳ᵛᵉᶜ, 𝒯, modeltype::EnergyModel) end
 function EMB.variables_capex(m, 𝒜::Vector{<:Area}, 𝒳ᵛᵉᶜ, 𝒯, modeltype::EnergyModel) end
@@ -503,7 +508,7 @@ end
     EMB.objective_operational(m, 𝒜::Vector{<:Area}, 𝒯ᴵⁿᵛ::TS.AbstractStratPers, modeltype::EnergyModel)
 
 Create JuMP expressions indexed over the investment periods `𝒯ᴵⁿᵛ` for different elements.
-The expressions correspond to the operational expenses of the different elements.
+The expressions correspond to the operating expenses of the different elements.
 The expressions are not discounted and do not take the duration of the investment periods
 into account.
 
@@ -551,6 +556,8 @@ function EMB.create_node(m, n::GeoAvailability, 𝒯, 𝒫, modeltype::EnergyMod
 
 Set all constraints for an [`Area`](@ref). Can serve as fallback option for all unspecified
 subtypes of `Area`.
+
+The default method does not add any constraints.
 """
 function create_area(m, a::Area, 𝒯, ℒᵗʳᵃⁿˢ, modeltype) end
 

diff --git a/src/structures/area.jl b/src/structures/area.jl
@@ -1,12 +1,12 @@
 """
-    Area <: AbstractElement
+    abstract type Area <: AbstractElement
 
 Declaration of the general type for areas.
 """
 abstract type Area <: AbstractElement end
 
 """
-    RefArea <: Area
+    struct RefArea <: Area
 
 A `RefArea` is an area representation with no additional constraints on energy/mass exchange.
 
@@ -27,7 +27,7 @@ end
 Base.show(io::IO, a::Area) = print(io, "$(a.name)")
 
 """
-    LimitedExchangeArea <: Area
+    struct LimitedExchangeArea <: Area
 
 A `LimitedExchangeArea` is an area in which the export is limited in each individual
 operational period for the provided resources. This can be necessary when an area is

diff --git a/src/structures/mode.jl b/src/structures/mode.jl
@@ -321,9 +321,9 @@ directions(tm::TransmissionMode) = tm.directions
 """
     has_opex(tm::TransmissionMode)
 
-Checks whether transmission mode `tm` has operational expenses.
+Checks whether transmission mode `tm` has operating expenses.
 
-By default, all transmission modes have operational expenses.
+By default, all transmission modes have operating expenses.
 """
 EMB.has_opex(tm::TransmissionMode) = true