The word ‘til is an abbreviated form of until. When spoken, the word ‘til is archaic but acceptable. That archaic quality, however, makes ‘til unacceptable in technical writing. More effective technical writers, therefore, will use the full word until, a more appropriate word for technical writing which minimizes confusion potentially created by its more nonstandard cousin.
It’s very common in speech to employ informal constructs. But more effective technical writing demands that writers avoid informality. So if you want more effective technical writing, don’t stop until you replace every ‘til in your document. More effective technical writing employs more precise language, and that produces a better presentation of both you and your brands in the minds of your audience.