适用于线性质量为35 kg/m或以上的钢轨，以及与这些平底钢轨相关的特殊截面。尤其不适用于槽轨和止回轨。投标邀请函通常应附有使用条件的定义和执行订单的其他文件。

Applies to rails with a linear mass of 35 kg/m or more and to special sections used in association with these flat bottom rails. Does not apply, in particular, to grooved rails and check rails. An invitation to tender should normally be accompanied by a definition of the conditions of use and other documents for carrying out the order.