S. Gilmer et al. report in this manuscript on the bioorthogonal fluorogenic chemistry of carbamate-caged dihydrotetrazines. The work is presented in two main parts: the first covers the synthesis, decaging, and oxidation of the dihydrotetrazine to the tetrazine, while the second focuses on the reactivity with BCN in the form of the IEDDA reaction. The authors carefully address the synthetic aspects (including the disclosure of formed isomers) as well as the photochemical properties.
The chemistry of such tetrazine-photo-decaging is challenging and I find the current report highly suitable for OBC. However, the article would benefit from a careful grammar check. I recommend publication after considering the following points:

• The motivation and introduction fall a bit short. For example, the first paragraph ends with ‘…particularly desirable for many applications.’ In my view, nanomedicine represents one of the most promising application areas for such photo-decaging, and several excellent reviews could be referred to (for example: Biomater. Sci., 2023,11, 1607-1624; ChemMedChem, 2017, 12, 23, 190).
• Figure 1A shows the oxidized pyridazine but reaction with TCO affords the non-oxidized product first.
• scheme 1: (from 3) – should this be ‘3’?
• On page 8, the authors speculate about the observed differences in oxidation reactivities in comparison with the work of Liu et al. I agree that the higher extend of conjugated system may attribute to such observation, but I also expect that the difference in wavelength has an impact. Did the authors expose the dihydrotetrazine to 405 nm and monitored oxidation?
• page 11: photo-trigged