Acrostic

An acrostic is a poem (or other form of writing) in which the first letter (or syllable, or word) of each line (or paragraph, or other recurring feature in the text) spells out a word, message or the alphabet. The word comes from the French "acrostiche" from post-classical Latin "acrostichis", from Koine Greek ἀκροστιχίς, from Ancient Greek ἄκρος "highest, topmost" and στίχος "verse". As a form of constrained writing, an acrostic can be used as a mnemonic device to aid memory retrieval.
Acrostics are common in medieval literature, where they usually serve to highlight the name of the poet or his patron, or to make a prayer to a saint. They are most frequent in verse works but can also appear in prose. The Middle High German poet Rudolf von Ems for example opens all his great works with an acrostic of his name, and his world chronicle marks the beginning of each age with an acrostic of the key figure (Moses, David, etc.). In chronicles, acrostics are common in German and English but rare in other languages.
Acrostic Form.
Relatively simple acrostics may merely spell out the letters of the alphabet in order; such an acrostic may be called an 'alphabetical acrostic' or abecedarius. These acrostics occur in the first four of the five chapters that make up the Book of Lamentations, in the praise of the good wife in Proverbs 31, and in Psalms 25, 34, 37, 111, 112, 119 and 145 of the Hebrew Bible.
Notable among the acrostic Psalms is the long Psalm 119, which typically is printed in subsections named after the 22 letters of the Hebrew alphabet, each section consisting of 8 verses, each of which begins with the same letter of the alphabet and the entire psalm consisting of 22 x 8 = 176 verses; and Psalm 145, which is recited three times a day in the Jewish services. Some acrostic psalms are technically imperfect. for example. Psalm 9 and Psalm 10 appear to constitute a single acrostic psalm together, but the length assigned to each letter is unequal and five of the 22 letters of the Hebrew alphabet are not represented and the sequence of two letters is reversed. In Psalm 25 one Hebrew letter is not represented, the following letter (Resh) repeated. In Psalm 34 the current final verse, 23, does fit verse 22 in content, but adds an additional line to the poem. In Psalms 37 and 111 the numbering of verses and the division into lines are interfering with each other; as a result in Psalm 37, for the letters Daleth and Kaph there is only one verse, and the letter Ayin is not represented. Psalm 111 and 112 have 22 lines, but 10 verses. Psalm 145 does not represent the letter Nun, having 21 one verses, but one Qumran manuscript of this Psalm does have that missing line, which agrees with the Septuagint.
Often the ease of detectability of an acrostic can depend on the intention of its creator. In some cases an author may desire an acrostic to have a better chance of being perceived by an observant reader, such as the acrostic contained in the "Hypnerotomachia Poliphili" (where the key capital letters are decorated with ornate embellishments). However, acrostics may also be used as a form of steganography, where the author seeks to conceal the message rather than proclaim it. This might be achieved by making the key letters uniform in appearance with the surrounding text, or by aligning the words in such a way that the relationship between the key letters is less obvious. This is referred to as "null ciphers" in steganography, using the first letter of each word to form a hidden message in an otherwise innocuous text. Using letters to hide a message, as in acrostic ciphers, was popular during the Renaissance, and could employ various methods of enciphering, such as selecting other letters than initials based on a repeating pattern (equidistant letter sequences), or even concealing the message by starting at the end of the text and working backwards.
Examples.
An acrostic was made in Greek for the acclamation "JESUS CHRIST, SON OF GOD, SAVIOUR". The initials spell ΙΧΘΥΣ (ICHTHYS), which means "fish":
 Ιησούς I "esoús" Jesus
 Χριστός CH "ristós" Christ
 Θεού TH "eoú" God's
 Υἱός Y "iós" Son
 Σωτήρ S "otêr" Saviour
There is an acrostic secreted in the Dutch national anthem "Het Wilhelmus" ("The William"): the first letters of its fifteen stanzas spell WILLEM VAN NASSOV. This was one of the hereditary titles of William of Orange (William the Silent), who introduces himself in the poem to the Dutch people. This title also returned in the 2010 speech from the throne, during the Dutch State Opening of Parliament, whose first 15 lines also formed WILLEM VAN NASSOV.
Vladimir Nabokov's short story "The Vane Sisters" is known for its acrostic final paragraph, which contains a message from beyond the grave.
An acrostic poem written in English by Edgar Allan Poe is entitled simply "An Acrostic":
<poem style="margin-left: 2em">
Elizabeth it is in vain you say
"Love not" — thou sayest it in so sweet a way:
In vain those words from thee or L.E.L.
Zantippe's talents had enforced so well:
Ah! if that language from thy heart arise,
Breath it less gently forth — and veil thine eyes.
Endymion, recollect, when Luna tried
To cure his love — was cured of all beside —
His folly — pride — and passion — for he died.
</poem>
Rolfe Humphries received a lifelong ban from contributing to Poetry Magazine after he penned and attempted to publish "a poem containing a concealed scurrilous phrase aimed at a well-known person", namely Nicholas Murray Butler. The poem, entitled "An ode for a Phi Beta Kappa affair", was in unrhymed iambic pentameter, contained one classical reference per line, and ran as follows:
<poem style="margin-left: 2em">
Niobe's daughters yearn to the womb again,
Ionians bright and fair, to the chill stone;
Chaos in cry, Actaeon's angry pack,
Hounds of Molossus, shaggy wolves driven
Over Ampsanctus' vale and Pentheus' glade,
Laelaps and Ladon, Dromas, Canace,
As these in fury harry brake and hill
So the great dogs of evil bay the world.
Memory, Mother of Muses, be resigned
Until King Saturn comes to rule again!
Remember now no more the golden day
Remember now no more the fading gold,
Astraea fled, Proserpina in hell;
You searchers of the earth be reconciled!
Because, through all the blight of human woe,
Under Robigo's rust, and Clotho's shears,
The mind of man still keeps its argosies,
Lacedaemonian Helen wakes her tower,
Echo replies, and lamentation loud
Reverberates from Thrace to Delos Isle;
Itylus grieves, for whom the nightingale
Sweetly as ever tunes her Daulian strain.
And over Tenedos the flagship burns.
How shall men loiter when the great moon shines
Opaque upon the sail, and Argive seas
Rear like blue dolphins their cerulean curves?
Samos is fallen, Lesbos streams with fire,
Etna in rage, Canopus cold in hate,
Summon the Orphic bard to stranger dreams.
And so for us who raise Athene's torch.
Sufficient to her message in this hour:
Sons of Columbia, awake, arise!
</poem>
In January 2010, Jonathan I. Schwartz, the CEO of Sun Microsystems, sent an email to Sun employees on the completion of the acquisition of Sun by Oracle Corporation. The initial letters of the first seven paragraphs spelled "Beat IBM".
James May, presenter on the BBC program "Top Gear", was fired from the publication "Autocar" for spelling out a message using the large red initial at the beginning of each review in the publication's "Road Test Yearbook Issue" for 1992. Properly punctuated, the message reads: "So you think it's really good? Yeah, you should try making the bloody thing up. It's a real pain in the arse."
In the 2012 third novel of his "Caged Flower" series, author Cullman Wallace used acrostics as a plot device. The parents of a protagonist send e-mails where the first letters of the lines reveal their situation in a concealed message.
On August 19, 2017, the members of President Donald Trump's Committee on Arts and Humanities resigned in protest over the President's response to the Unite the Right rally incident in Charlottesville, Virginia. The members' letter of resignation contained the acrostic "RESIST" formed from the first letter of each paragraph.
On August 23, 2017, University of California-Berkeley energy professor Daniel Kammen resigned from his position as a State Department science envoy with a resignation letter in which the word "IMPEACH" was spelled out by the first letters of each paragraph.
In the video game Zork the first letters of sentences in a prayer spelled "Odysseus" which was a possible solution to a Cyclops encounter in another room.
Multiple acrostics.
Acrostics can be more complex than just by making words from initials. A double acrostic, for example, may have words at the beginning and end of its lines, as this example, on the name of Stroud, by Paul Hansford -
 S et among hills in the midst of five valley S,
 T his peaceful little market town we inhabi T
 R efuses (vociferously!) to be a conforme R.
 O nce home of the cloth it gave its name t O,
 U phill and down again its streets lead yo U.
 D espite its faults it leaves us all charme D.
The first letters make up the acrostic and the last letters the telestich; in this case they are identical.
The poem "Behold, O God!", by William Browne, can be considered a complex kind of acrostic. 
In the manuscript, some letters are capitalized and written extra-large, non-italic, and in red, and the lines are shifted left or right and internally spaced out as necessary to position the red letters within three crosses that extend through all the lines of the poem. 
The letters within each cross spell out a verse from the New Testament:
The "INRI" at the top of the middle cross stands for "Iēsus Nazarēnus, Rēx Iūdaeōrum", Latin for "Jesus of Nazareth, King of the Jews" (). The three quotes represent the three figures crucified on Golgotha, as recorded in the gospels of Matthew and Luke.
<poem style="margin-left: 2em">
Behold, O God! In rivers of my tears
I come to thee! bow down thy blessed ears
To hear my Plaint; and let thine eyes which keep
Continual watch behold a Sinner weep:
Let not, O God my God my Sins, tho' great,
And numberless, between thy Mercy's-Seat
And my poor Soul have place; since we are taught,
"[Thou]" Lord, remember'st thyne, if Thou art sought.
I come not, Lord, with any other merit
Than what I by my Saviour Christ inherit:
Be then his wounds my balm— his stripes my Bliss;
His thorns my crown; my death be blest in his.
And thou, my blest Redeemer, Saviour, God,
Quit my accounts, withhold thy vengeful rod!
O beg for me, my hopes on Thee are set;
And Christ forgive me, since thou'st paid my debt
The living font, the Life, the Way, I know,
And but to thee, O whither shall I go?
All other helps are vain: grant thine to me,
For in thy cross my saving health I see.
O hearken then, that I with faith implore,
Lest Sin and Death sink me to rise no more.
Lastly, O God, my course direct and guide,
In Death defend me, that I never slide;
And at Doomsday let me be rais'd again,
To live with thee sweet Jesus say, Amen.
</poem>
 Behold, O God! IN RI vers of my tears
 I come to thee! bow down thy blessed ears
 To hear my Plaint; and let thine eyes which keep
 Continual watch behold a Sinner weep:
 Let not, O GOD my GOD my Sins, tho' great,
 And numberless, bet W een thy Mercy's-Seat
 And my poor Soul H ave place; since we are taught,
 "[Thou]" Lord, remember st th Y ne, If Thou art sought.
 I co ME not, Lord, wit H any o THE r merit
 Than WH at I by my S A viour CH rist inherit:
 Be th EN his Wound S my Balm— his St RI pes my Bliss;
 His TH orns my crown; my dea T h be ble ST in his.
 And th OU, my bles T Redeemer, SA viour, God,
 Quit my ac CO unts, with H old thy VE ngeful rod!
 O beg for ME, my h O pes on T hee are set;
 And Chri ST forgi V e me, since t H ou'st paid my debt
 The liv IN g font, the Li F e, the Wa Y, I know,
 And but TO thee, O whither S hall I go?
 All o TH er helps a R e vain: grant thin E to me,
 For in th Y cross my S aving hea L th I see.
 O hear K en then, th A t I with F aith implore,
 Lest S IN and Death sin K me to rise + no more.
 Lastly, O G od, my cours E direct A nd guide,
 In D eath defe N d me, that I N ever slide;
 And at Do OM sday let M e be rais' D again,
 To live + with the E sweet Jes US say, Amen.