The National Statistics definition of suicide is given in "Things you need to know about this release" section of this bulletin.
'Other' category includes methods of suicide such as firearm, contact with sharp object and jumping/lying in front of a moving object.
Figures are for persons aged 10 years and over.
Deaths of non-residents are included in figures for England and Wales.
Figures are for deaths registered, rather than deaths occurring in each calendar year. Due to the length of time it takes to complete a coroner's inquest, it can take months or even years for a suicide to be registered. More details can be found in the Quality and methodology section.
Table 19 in the reference table, named 'Suicide in the United Kingdom', has more information regarding definitions.