Disable tags sanitizing

Hello! I need to migrate from one forum system to Discourse. I move posts with Discourse api /posts.json. Some posts have html tags in bodies. How can I temporarily disable discourse baking with sanitizing? Or how can I rebake?

For example, we have some post with body like this:

someUrl?param=<someParam>

Discourse thinks that <someParam> is html tag and he removes it completely.

Does anybody know how to deal with it?

It may help if you specify what the “one forum system” is. There are several existing migration scripts and if the one you need isn’t available it’s possible what you need could be put together.