When Holy Words Meet the Whiteboard Eraser
Written words of Torah attain kedushah (sanctity) and must be treated with respect. If a teacher writes the day’s Torah lesson on a blackboard or whiteboard, may it then be erased?
The common custom is that it may (and the practice of using the board to teach Torah persists), for two reasons. The first suggests that words written with the intention of erasing them afterwards do not acquire kedushah. Alternatively, it's possible to say that the purpose of erasing the board is to make it available for more Torah to take its place.
Nevertheless, the name of Hashem should not be written, as it may never be erased. It is customary not to write Hashem’s name in full, in any language; so we write, for example, “With G-d’s help.” However, if Hashem’s name was written without modification in another language, it may be erased from the board.
It is a time-honored tradition for headings—on papers, posters, and on the board in the classroom—to begin with a reference to Hashem’s immanence, commonly written as such: בס"ד, which is the Hebrew acronym for Bi’Siyata D’Shmaya (With Hashem’s help). This too may be erased. Even writing the alternative ב"ה, which stands for Baruch Hashem (this acquires a higher status of kedushah, as the letter hey [ה] is a stand-in for Hashem’s holy name) may be erased from the board, though some maintain that it's preferable to write בס"ד (BSD).