diff --git a/docs/2____common_concepts.adoc b/docs/2____common_concepts.adoc
index 93c8db18..489d31e9 100644
--- a/docs/2____common_concepts.adoc
+++ b/docs/2____common_concepts.adoc
@@ -116,16 +116,13 @@ The usage of this architecture type allows the integration of this layered stand
 In this case, it may also be possible to integrate other, for example manufacturer-specific, formats into a bus simulation.
 
 ===  Provided C-API [[common-concepts-provided-c-api]]
-Besides the textual specification for FMUs with bus support, this layered standard also provides a C-API to make the creation of FMUs with bus support as easy and generalized as possible.
-The standard differentiates between two groups of files within the C-API: Mandatory and optional files.
+Besides the textual specification for FMUs with bus support, this layered standard also provides a C header files to simplify the creation of FMUs with bus support.
+The following header files are provided:
 
 * https://github.com/modelica/fmi-ls-bus/blob/main/headers/fmi3LsBus.h[fmi3LsBus.h] provides general macros, types and structures of common Bus Operations.
 These header file applies to all supported bus types of the layered standard.
-The usage of this file is mandatory.
 * https://github.com/modelica/fmi-ls-bus/blob/main/headers/fmi3LsBusCan.h[fmi3LsBusCan.h] provides macros, types and structures of Bus Operations explicit for CAN, CAN FD and CAN XL.
 Primarily, structures are included here that allow the Bus Operations specified by the layered standard to be easily created and used.
-The usage of this file is mandatory.
 * https://github.com/modelica/fmi-ls-bus/blob/main/headers/fmi3LsBusUtil.h[fmi3LsBusUtil.h] provides common utility macros and structures for all supported bus types.
-The usage of this file is optional.
 * https://github.com/modelica/fmi-ls-bus/blob/main/headers/fmi3LsBusUtilCan.h[fmi3LsBusUtilCan.h] provides CAN, CAN FD and CAN XL explicit utility macros.
-The usage of this file is optional
+