It makes sense to have a two-letter mint mark, as Budapest is the result of the unification of the cities of Buda and Pest in 1873.
The arms on this coin are now obsolete, as Hungary has reverted to its pre-communist arms. The shield is in the colours of the Hungarian flag, red-white-green. The shield holder is two ears of wheat, bound with a ribbon at the bottom and topped with a lone star. The star is a well-known symbol of communism and Texas, while the wreath stands for agriculture, so the symbolism seems to say communism is shining on agriculture and the Hungarian nation. Conspicuously missing is a reference to industry. The communist hammer and sickle logo refers to industry and agriculture. In communist economic theory they are the only productive services in the economy. Services and government are non-productive. Both were supposed to be replaced by brotherly love in the final stage of communist development.
Other communist countries (China and North Korea come to mind) also struggled with the industry-agriculture symbolism, primarily because they had little or no industry. However, Hungary did have an industry, making the absence of it in the symbology remarkable.
Peter