If an app is unsuccessful, how long until one can reapply?

[sgc]

I thought I read somewhere that if an application is unsuccessful then one can apply again in 1 year from the date of the previous application, but on a recent search I haven't found it mentioned in the guide or website. Can anyone help? Thanks.

[Amber]

When you're eligible to apply. Make sure you meet the requirements before you apply.

[sgc]

The applicant would probably have to wait about a year anyway to be eligible for applying if they don't apply during a certain range this year, due to otherwise being outside of the UK 5 years before the date until then. Since the eligibility issue in this case is technically a grey area I'm not sure whether they should apply this round. Does it harm an application if a prior application was unsuccessful?