Wittgenstein's Tractatus presented the philosophical community with an enigma: Wittgenstein said of it that "..anyone who understands me eventually recognise [my Tractarian propositions] as nonsense" (T. 6.54), and "the truth of the thoughts that are here communicated seems to me unassailable and definitive" (T..preface)
The two camps of Tractarian opinion suggest that either the whole work was in Witt's eyes mere nonsense, that being the end of it, or that he used "elucidatory" "nonsense" to evoke a syntactically inexpressable mystery. I suggest, there is no conflict between the idea of the Tractatus as both nonsense and truth if we take a transcendental view, specifically a transcendentally ideal (after Kant) view.
Here, objects, such as the elements of a syntax, do not arise independently as if taking on the properties of their appearance, but require conditions that set up the limits, physical or epistemological, for their appearance. Without those conditions the syntax is nonsense in the sense of gibberish, but with those conditions in (their rightful) place, they can be identified as existing and subject to truth and falsity. Simply to exist is not a sufficient criterion for the appearance or manifestation of an object.
"Truths" pertain only to syntax, and not to the transcendental conditions that identify the objects or elements of a syntax. Authors elsewhere (see Badiou) speak of "truths" and "acts" in the same way. In the Tractatus Wittgenstein was driven by the idea that propositions deliver their meaning syntactically, where each element contributes as a summation or total to the meaning of the proposition. The elements of the syntax of the Tractatus that are subject to assessments of truth are his logical propositions. These are modelled on a physical syntax or behaviour, like the syntax of mathematics. Truths refer, then, only to the elements of that syntax, their structures, position and behaviours or its "ontology". Thus for Wittgenstein, Tractarian truths really are truths. Just like, for example, it is true that this element or object is (or is not) behind that element or object. These are syntactical truths for a physical ontology. There are other ontolgies.
"Nonsense", on the other hand, refers 1) to the necessarily failed attempt of any syntax (Tractarian propositions in this case) to describe that framework that selects or identifies syntactical elements and, 2) to the gibberish of any supposed syntax that attempts to offer its services to meaning without its identifying condition. Thus, the propositions, elements, or syntax of the Tractatus could not of themselves be configured in such a way that they could describe their own identifying framework, rather they must show it simply by being said or expressed. For example, in a bouquet the syntax of flowers, or set (sum or total) of flowers, could never of themelves describe, identify or manifest the bouquet. In this case the set of flowers correspond to the propositions of the Tractatus and their manifesting conditions, the bouquet, are the propositions of the Tractarian preface, in this fashion:
Wittgenstein could say of the Tractarian text but in the body of the Tractarian text that his propositions were nonsense or elucidations where they assert, manifest or identify themselves; and he could say, without conflict, but only in the preface to the text, that these same propositions were true where the preface is the transcendental, identifying, or manifesting condition of the propositions or elements within the Tractarian text. Without that identifying condition they are, indeed, nonsense. Yet as truths, they appear unchanged, as they were written.
Wittgenstein said that logic was transcendental, but he did not directly distinguish between transcendentally real and ideal. He may have meant to use the term in its unexpanded form to describe a vision of logic as transcendent and ineffable, as an absolute that cannot itself be described or said, except through its elements or syntax. This vision may have prevented full expression of what he must have intuited. This barely expressed intuition of Wittgenstein is that the Tractarian text and preface appear together as a trancendentally ideal undertaking in which the syntax expresses true propositions; but considered on its own merits - without the transcendentally ideal condition for its identification, appears as expressed nonsense offering a set of trancendentally real propositions that in turn offer a transcendent logic that asserts, but is unable to identify, its own syntax.