In international shipping, there is a clear distinction between the tramp and linear forms of shipping. Tramp trade is characterized by a lack of systematic transportation. Typically, for tramp shipping, a carrier is not connected to a permanent navigation area, ports of loading and unloading. The cost of such transportation is established by agreement of the parties and depends on the market of transport services.

The linear form of shipping is characterized by its regularity, the consolidation of ships to the sea lines. The implementation of traffic in such shipping involves the movement of ships between certain ports on a previously announced schedule, or with a certain established frequency.接单（接受货主委托）
接受货主委托后（一般为传真件）需明确的重点信息：
1. 船期、件数
2. 箱型、箱量
3. 毛重
4. 体积
各项型最大体积为：( 长＊宽＊高 ) 可装体积， 可装重量
1×20＇GP=31CBM 6＊2．38＊2．38　25　17MT
1×40＇GP=67CBM 12＊2．38＊2．38　55　25MT
1×40＇HC=76CBM 12＊2．7＊2．38
1×45，GP=86CBM
（注：GP: general purpose 普通箱；CBM: cubic metre 立方米；MT: metric ton 公吨 ；HC: high cubic 高箱 ）
5. 付费条款、货主联系方法
6. 做箱情况，门到门还是内装