In many ways, Dalzell's is an exemplary slang dictionary, as one might expect from so experienced a slang lexicographer. Slang dictionaries do not usually explain the principles underlying inclusion, the selection of headword forms, the ordering of senses and the designation of country of origin, although this information is vital to any careful user.

Dalzell offers a snapshot of ‘slang learned and used in Vietnam, some of which was then later used back home’ (x) rather than an account of slang first used in Vietnam. He therefore includes many terms that predate the war as well as some that were recorded only in post-war accounts and dictionaries. However, although the wordlist has evidently been compiled, at least in part, from the New Partridge (NP), it is not clear how NP entries that were not specifically labelled as belonging to the Vietnam War were selected. It would not have been possible to document general US and military slang from this period in full in this dictionary, so it would have been useful to explain why, for example, motherfucker ‘a fellow, a person’ is included, while fuck ‘to have sex (with)’ is not. Some recruits, surely, learnt both of these terms in Vietnam. Although the character of Rambo is undoubtedly associated with Vietnam, no evidence is provided to demonstrate that Rambo – “a soldier with too much of a sense of drama and too little intelligence” - was ‘learned and used in Vietnam’ from David Morrell's novel First Blood (1972) rather than the (post-Vietnam) 1982 film of the same name.

The guide to the ‘structure of the entries’ explains that dates following definitions indicate ‘a known citation that is earlier than the earliest citation given here’ (viii), and these often correspond with the equivalent dates in NP (e.g. cherry ‘a soldier newly arrived in combat’, desk jockey ‘an office worker’, hairy ‘dangerous, scary (especially if thrilling)’, honey bucket ‘a chamberpot’). However, while NP alludes to a UK citation from 1921 for gong ‘a military decoration, a medal’ it is labelled here as ‘US 1991’. Similarly hot bunk ‘to sleep in shifts on a given bunk or bed’ is dated to 1980 although NP has a citation from 1945. Motherfucker is dated to 1958, though NP dates it to 1928 (and the OED to 1918).

These dating disparities interplay with uncertainties around sense divisions. Tail-end Charlie ‘the rearmost helicopter in a combat formation’ is labelled ‘US 1991’, where NP has ‘UK 1941’ for the sense ‘someone at the rear of any group or expedition’. Beale's edition of Partridge's DSUE indicates that it referred not just to people but also to aircraft, and dates this usage to WWII. This suggests that minor changes in reference (aeroplane → helicopter) trigger new sense distinctions, and that the ‘known citation’ dates reflect this level of precision. However, re-up ‘to replenish a stack of something; to resupply something; to re-sign or re-enlist’, ‘originally a military slang term for re-enlisting’, combines two quite different senses, making it difficult to interpret the single ‘known citation’ date of 1906. The inclusion of sham ‘to fabricate an injury or aggravate a real injury in the hope of being sent home’ appears to depend on its inclusion with this definition in Reinberg's In the Field (1995) rather than from a meaningful difference between this sense and the more general ‘to deceive, to hoax, to fool; to pretend to be or do something’ (GDoS, 1688).

The absence of a ‘known citation’ date might be thought to indicate Vietnam War origins, but for many terms the picture is more complex. For example, funny money ‘military payment certificates’ does appear to be restricted to Vietnam with this sense, but the OED lists various other uses with reference to counterfeit or play money from 1938. Similarly, strap-hanger ‘a member of the armed forces, stationed well away from combat, accompanying troops into the field without having a specific role to play’ is comfortably antedated by the OED's ‘A passenger who is compelled to stand and hold on by the strap in a full omnibus, compartment of a railway carriage, etc.; also fig., one who commutes to work by public transport’ (1905). It might be argued that no ‘known citation’ date is supplied because these are senses originating in Vietnam, but this argument does not explain the absence of a ‘known citation’ date for hop ‘a stage of a flight’ (OED, 1902) and lead pill ‘a bullet’ (HDAS, 1850s).

The ‘structure of the entries’ guide explains that where a country of origin is given it is ‘the origin of the earliest citation found’, a principle also observed in NP. This introduces additional uncertainties. For example, recky ‘reconnaissance’ is labelled as ‘US’ although NP labels it ‘UK’. Without a date, it is impossible to determine whether this change represents the discovery of an earlier ‘known citation’.

There were other places where I felt the absence of information that a speaker of American English might not have needed. For example, the capitalization in CARE package ‘a box of treats and/or necessities, sent to someone away from home with the hope of cheering them up’ implied that CARE was an acronym, but I had to consult the OED to find its origin in ‘the initial letters of Cooperative for American Remittances to Europe’. Similarly land of the big PX ‘the United States’ did not make sense to me without the OED definition for Post Exchange ‘a shop at a military post where goods and services are available to military personnel and authorized civilians; abbreviated PX’.

Vietnam War Slang is a fascinating compilation from earlier dictionaries and from contemporary and post-war Vietnam literature. Properly interpreted and used alongside other dictionaries, it makes a useful contribution to knowledge. However, it offers much scope for misinterpretation by unwary users.