Classification is a very important part of the Paralympics, with each event name preceded by a different code. 

This code refers to the level of impairment, with athletes competing in events in line with their individual disabilities. 

The aim is to make the competition as fair as possible by grouping athletes with similar impairments into different classes for each sport. 

With ParalympicsGB's Libby Clegg a big medal hope in the women's T11 200m, here's what you need to know about the event...

What does T11 mean?

Events classified as T11-13 refer to running and jumping events for athletes with severe visual impairments. 

The lower the number, the more severe the impact of the disability. 

For example, T11 athletes will have little to no light perception and in many cases are completely blind. 

As the number increases, the visual impairment decreases: T12 athletes will have better vision than T11 athletes, while T13 athletes are the least visually impaired of all in these categories. 

T13 athletes can typically recognise contours from 2-6 metres.

What does F11 mean? 

With the F standing for Field, events classified as F11-13 refer to throws and follow a similar pattern to the track events, with F11 athletes the most severely visually impaired.

What is a guide?

Guides are compulsory for athletes competing in T11 events, and optional for those competing in T12 events.

Guides are not typically used in T13 events. 

A guide is a runner who is not visually impaired and is attached to the impaired competitor using a band at the hand or wrist. 

They are responsible for informing their partner where they are in the field and how far along the track they are.

Successful pairs run in complete unison, but the guide cannot cross the line first or the duo will face disqualification. 

The guide is also not permitted to pull the visually impaired athlete along, and doing so will face disqualification. 

What event does Libby Clegg compete in?

Libby Clegg is one of ParalympicsGB's famous faces, with Tokyo 2021 marking her fourth games. 

She is no stranger to success, having won the double in Rio across the T11 100m and T11 200m with guide Chris Clarke. 

This year she will partner Clarke again as they hope to defend their T11 200m Paralympic title. 

It comes after a difficult year in 2020 when Covid restrictions meant Clegg had to abandon her training with social distancing requirements preventing her from being  tethered to her guide.