Employment in the IT industry falls into the 2 principal areas of support and development. Although development might be perceived as anything new, it generally refers to producing new applications for computers. Although support can be viewed as involving the support of existing programs, it's normally considered as technical support, in one way or another.
A recruitment agency will obtain a fairly good idea of where best a jobseeker fits in the IT industry, based on his/her CV. Job titles such as "Helpdesk Supervisor," "PC Support Technician," "Java Developer" or "Cobol Programmer" can provide them with an indication of what the IT candidate is capable of. On the other hand, IT job role titles like "Systems Engineer" or "ICT Officer" might be too vague or are not clear enough in describing what the candidate actually does - this is where things could become difficult. Fortunately, many people who send a CV of this nature to an employer will back up the job role title with info on his/her actual skills (although this isn't necessarily always the case, with some people leaving the recruiter puzzled over what it is they do).
When a recruiter gets hold of and peruses the CV, everything will become obvious, however there's still the matter of the employer even finding their CV to begin with. A lot of recruitment firms use job boards and so-called CV databases to find CVs, downloading the ones of interest. This can be where deciding on the correct role title is imperative, as employers might look for terms like "C++ Software Engineers" or "Java Developers" but maybe not necessarily more vague terms like "ICT Officers." Therefore, jobseekers labelling themselves things including the latter could have less of a chance of getting noticed for the IT job that they're after.
Job ads are also influenced in exactly the same way. Advertising for a job like "Applications Support Analyst" might not aim attention too clearly on what it is a jobseeker is searching for, whereas a title like ".Net Developer" is a lot clearer. It's the aforementioned factor turned around - rather than an employer not discovering a candidate based on their CV, a jobseeker can't find an advert based on its title and wording.
In order to know how to pitch themselves or their adverts, jobseekers and recruiters have to recognise the significance of the types of IT job roles out there and what they might be named or referred to by a larger audience. If they do so, they'll do better in coming across the right jobseeker or job role due to being able to come across one another much easier.