Ancient poetic forms seem to have had more rigorous rules to follow. I sure wouldn’t be able to write a poem worth anything following these rules.
Alcaic, n. and adj.
A poem, strophe (stanza), or line written in Alcaic metre (see sense B.). Usually in plural.
Written or composed in a metre traditionally attributed to Alcaeus; relating to or characteristic of this metre or verse written in it.
An Alcaic strophe in Greek and Latin poetry consists of four metrical units or lines, two of eleven syllables, followed by one of nine syllables and one of ten, each with a distinctive pattern of long and short syllables, and with a word-end after the fifth syllable in each of the first two lines. The metrical pattern of each line is used in other types of stanza and other forms of verse.