Decision Assessment Document; Shea v. Wilkie, June 20, 2019, 926 F. 3d 1362 (Fed. Cir. 2019); where claimant’s filings refer to specific medical records, and those records contain a reasonable ascertainable diagnosis of a disability, the claimant has raised an informal claim for that disability under 38 C.F.R. 3.155(a);