/usr/include/ is in libsml-dev 0.1.1+git20170608-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sml/
/usr/include/sml/sml_attention_response.h
/usr/include/sml/sml_boolean.h
/usr/include/sml/sml_close_request.h
/usr/include/sml/sml_close_response.h
/usr/include/sml/sml_crc16.h
/usr/include/sml/sml_file.h
/usr/include/sml/sml_get_list_request.h
/usr/include/sml/sml_get_list_response.h
/usr/include/sml/sml_get_proc_parameter_request.h
/usr/include/sml/sml_get_proc_parameter_response.h
/usr/include/sml/sml_get_profile_list_request.h
/usr/include/sml/sml_get_profile_list_response.h
/usr/include/sml/sml_get_profile_pack_request.h
/usr/include/sml/sml_get_profile_pack_response.h
/usr/include/sml/sml_list.h
/usr/include/sml/sml_message.h
/usr/include/sml/sml_number.h
/usr/include/sml/sml_octet_string.h
/usr/include/sml/sml_open_request.h
/usr/include/sml/sml_open_response.h
/usr/include/sml/sml_set_proc_parameter_request.h
/usr/include/sml/sml_shared.h
/usr/include/sml/sml_status.h
/usr/include/sml/sml_time.h
/usr/include/sml/sml_transport.h
/usr/include/sml/sml_tree.h
/usr/include/sml/sml_value.h