:The description is pithy, accurate, informative, relevant, and agreed upon by the authorities on the subject.  Those 2 lines deliver more information to a person completely ignorant on the subject (that would most likely be visiting this page and not a specific tank) than the entire rest of the lead put together, which at present doesn't tell the reader what a tank is, or how it provides a direct fire role.  If the lead were properly written and formatted it would include all the information in those two lines, however it's unlikely it could defeat the quote in terms of brevity or readability.  I believe the quote would be a valid inclusion even if there were some lack of consensus as to what a main battle tank is, but there isn't, which is just further reinforcement. I could understand the hesitation if it were a legal definition within the boundaries of a nation, like the definition of assault varies from district to district - but the CFE treaty has been signed by every builder of main battle tanks in the world, excluding the Chinese, who would probably agree anyway.  It is an impeccably written piece of legislation that would be a valuable addition to the article in verbatim, even without the quotes, and sourced from a place as reliable as this just compounds the effect.