YAGNI

From Fresh Dictionary

English

Acronym

1. (software engineering) ((informal{{#if:|, {{{2}}}{{#if:|, {{{3}}}{{#if:|, {{{4}}}{{#if:|, {{{5}}}{{#if:|, {{{6}}}{{#if:|, {{{7}}}{{#if:|, {{{8}}}{{#if:|, {{{9}}}}}}}}}}}}}}}}}}}))

You ain't (or sometimes aren't) gonna need it; a reminder to software developers not to add functionality to software until it is required.