据你所知，一般销售合同中如果付款条件中有rentention条款的，公司会把它当作revenue吗？
好像这样：
Sales Order with total amount $10000
Retention Cap $500
Milestone 1
1/6/11 $1800 (payment in 30 days, after retention)
1/6/11 $200 retention (10%) (in 2 years)
Milestone 2
1/10/11 $2700 (payment in 30 days)
1/10/11 $300 retention (10%) (in 2 years)
Milestone 3
1/05/12 $5000 (payment in 30 days)

还是不当它revenue，好像这样？

Milestone 1
1/6/11 $1800 (payment in 30 days)
Milestone 2
1/10/11 $2700 (payment in 30 days)
Milestone 3
1/05/12 $5000 (payment in 30 days)
Milestone 4 (retention)
1/3/2013 $200 (payment in 30 days)
1/3/2013 $300 (payment in 30 days)

日期是billing date.