stand for,stand in for,take the place of的联系与区别?

stand for
1.代表;象征
The American flag stands for freedom and justice.
美国国旗代表自由及公平.
What do the letters UN stand for?
字母UN代表什么?
2.主张;支持,拥护
We stand for self-reliance.
我们主张自力更生.
take the place of
代替
Nowadays plastics have taken the place of many conventional materials.
现在塑料已代替了许多传统材料.
stand in for
貌似意思为“站在为.”