Huntinality 2022/Morose Codes

Morose Codes is a minimalist puzzle from the CTO round of Huntinality 2022. The puzzle contains very little content—its ten lines are each a short string of capital letters.

Solve Path
The most conspicuous hint on what to do with each line comes from the title, "Morose Codes"—just one letter off "Morse Codes". Further confirmation comes from the selection of letters used in each line—some have a shared property in Morse code. The first line, for instance, only uses letters requiring two inputs in Morse (I, A, N, M).

From there, solvers might note a number of interesting patterns in the dots and dashes. One particular line that stands out is the sixth, which is dominated by long runs of dots with a few dashes interspersed in between. Counting up the number of dots in each run and indexing them into the alphabet yields, which can be error-corrected to.

Regardless of the string they end up breaking into, the solvers may realize that the string they just obtained is a hint towards the decryption of another string. The whole list of decryptions follow:


 * - Solvers might recognize that digits in Morse Code consist of five inputs spanning at most two runs of consecutive dots or dashes. Line 2 fits this bill (and conveniently is chunked such that each bigram has a total of five inputs); it deciphers to.
 * - Line 5 doesn't seem to stand out much in terms of the letters it uses. Counting the number of inputs, however, reveals that it has exactly 26 inputs, one for each letter of the alphabet. Taking the letters at the dots reveals a compelling anagram of BINARY with an extra E.
 * - Binary, especially the five-bit variation, is a common puzzlehunt extraction. Line 10, much like line 2, is conveniently chunked into bigrams of five inputs each; interpreting them as five-bit binary yields.
 * - Here, solvers can reverse the messages and attempt to read off a coherent message. The most compelling is line 9, reading.
 * - Solvers can try every message to see which one fits the transformation. This is revealed to be line 7, reading.
 * - Braille letters are written using a binary 3x2 grid. One of the Morse messages provides such a grid by only using the two-input letters: line 1. Taking each three-letter chunk as a single Braille letter reveals.
 * - Line 8 only uses the three-input letters. Arranging them into a three-wide grid reveals that the dashes spell out.
 * - Solvers might recognize Tap Code as converting between letters and pairs of numbers between 1 and 5. Line 4 notably contains only letters that exclusively use one of dots or dashes, and the runs are between 1 and 5 inputs long. Treating each run as a number and converting reveals.
 * - Solvers can try every message to see which one fits the transformation. This turns out to be line 3, reading.
 * - At this point, solvers realize that they have come back to line 6, since it uses the unary extraction (i.e. counting dots). The answer here is.

As it turns out, every decryption contains an extra letter; this is the extraction.

Solvers may also note that the strings are arranged alphabetically. Conveniently, the hints given by the decryptions form a cyclical ordering; using this to order the letters reveals the answerphrase.

Track Differences
Like most of the puzzles in this hunt, this puzzle has a casual and an expert version. The changes here are minimal, however—the casual version only gets a single additional line of flavortext:

Step 1: Convert to Morse Code.