The SBL Handbook of Style blog has a helpful post about the placement of citations in the footnote-bibliography, or traditional, style. Of particular interest is the section related to “Bibliographic Information inside Footnotes.”
According to the Chicago Manual of Style (17th ed.), when presenting a long citation to support material provided in a content or commentary footnote, the citation should typically be presented as its own sentence (§14.38; see also §§14.37, 14.39):
When a note includes a quotation, the source normally follows the terminal punctuation of the quotation. The entire source need not be put in parentheses, which involves changing parentheses to brackets (see 6.101) and creating unnecessary clutter.
Then, the Chicago Manual gives the following note as an example:
1. One estimate of the size of the reading public at this time was that of Sydney Smith: “Readers are fourfold in number compared with what they were before the beginning of the French war.… There are four or five hundred thousand readers more than there were thirty years ago, among the lower orders.” Letters, ed. Nowell C. Smith (New York: Oxford University Press, 1953), 1:341, 343.
This situation is exemplified in the SBL Handbook of Style blog post paragraph “When a quotation or a discussion inside a footnote is followed by a full reference….”
According to the Chicago Manual’s example above, the same format appears to occur when an element from the citation (e.g., the author’s name, “Sidney Smith,” in the example) is not repeated in the citation.
For the SBL Hansbook of Style, however, relocating the author’s name to the body of the sentence within the footnote requires that even an otherwise full footnote be included in parentheses.
Consequently, any parentheses in that footnote would need to shift to square brackets. Thus, SBL style prefers what the Chicago Manual deems “unnecessary clutter”:
Correct: 97. Cyrus H. Gordon argued that brh in Isa 27:1 should be translated “evil,” based on an Arabic cognate (“Near East Seals in Princeton and Philadelphia,” Or 22 : 243; see also Gordon, Ugaritic Textbook, AnOr 38 [Rome: Pontifical Biblical Institute, 1965], 376).
For SBL style, when a given source supports an intra-footnote comment and has previously been cited, then the citation for the intra-footnote comment is given in parentheses. Thus, in the post’s examples:
Correct: It is interesting to note that Richards also seems to anticipate Lakoff and Johnson’s basic definition of metaphor when he writes that metaphor includes “those processes in which we perceive or think of or feel about one thing in terms of another” (Richards, Philosophy of Rhetoric, 116–17).
Correct: 55. Entailments are “rich inferences” or knowledge (“sometimes quite detailed”) that we can infer from conceptual metaphors (Evans and Green, Cognitive Linguistics, 298–99).
By comparison, according to the Chicago Manual (§14.39),
Substantive, or discursive, notes may merely amplify the text and include no sources.… When a source is needed, it is treated as in the example in 14.38 [quoted above] or, if brief and already cited in full, may appear parenthetically…
The Chicago Manual then gives the following example note:
1. Ernst Cassirer takes important notice of this in Language and Myth (59–62) and offers a searching analysis of man’s regard for things on which his power of inspirited action may crucially depend.
These comments in the Chicago Manual could suggest that (a) notes of this type should have only page numbers included in parentheses and (b) other information necessary to the citation would need to be included in the prose of the footnote sentence itself.
So, for users of SBL style, the blog discussion helpfully clarifies how that style prefers to handle citations for content included within footnotes.