Not really, depending on who you ask. In the 90s, the RAE declared that ‘ll’ and ‘ch’ were no longer letters, but they’re still taught as letters in many places

Not really, depending on who you ask. In the 90s, the RAE declared that ‘ll’ and ‘ch’ were no longer letters, but they’re still taught as letters in many places. ‘rr’ was never a letter in its own right, but many people consider it to be, as a kind of parallel to ‘ll’ and ‘ch’.