RE: PB Notable [b]rackets in Space Policy Directive
the MLA Handbook advises, “Unless indicated in square brackets or parentheses, changes must not be made in the spelling, capitalization, or interior punctuation of the source” (75). Let’s say your original source reads as follows:
Poets are the unacknowledged legislators of the world.
If you need to lowercase the initial letter of the first word to fit the quotation syntactically into your sentence, indicate the change in brackets:
In “A Defence of Poetry,” Shelley argues that “[p]oets are the unacknowledged legislators of the world.”
Work Cited
Shelley, Percy Bysshe. “A Defence of Poetry.” Poetry Foundation, 13 Oct. 2009, www.poetryfoundation.org/articles/69388/a-defence-of-poetry.
https://style.mla.org/changing-initial-capital-letter/