This is Jesus the King of the Jews
27 And above His head they put up the charge against Him which read, “THIS IS JESUS THE KING OF THE JEWS.”
Matthew 27:37  NASBu

The King of the Jews
26 The inscription of the charge against Him read, “THE KING OF THE JEWS.”
Mark 15:26  NASBu

This is the King of the Jews
38 Now there was also an inscription above Him, “THIS IS THE KING OF THE JEWS.”
Luke 23:38  NASBu

Jesus of Nazareth, the King of the Jews
19 Pilate also wrote an inscription and put it on the cross. It was written, “JESUS THE NAZARENE, THE KING OF THE JEWS.”
John 19:19  NASBu

SAB Contradiction 922 (by book)

What is the Bible Contradiction?

Is there a contradiction in meaning between the four reported signs at the cross? No. Is there a difference in wording? Yes. What then is the problem? That is: If the Bible is accurate according to the Christians, it is a contradiction when the Bible is inaccurate in reporting. Isn’t it? Let’s have a look.

First observations

Considering the four statements we may take that the sign over Jesus’ head contained four parts:
(Opening) This is, (Name) Jesus, (Origin) of Nazareth, (Guilt/Accusation) The King of the Jews.
Matthew and Mark give “the accusation” (the charge). Luke gives “an inscription”. Neither of them claims to give the full writing.

It is most interesting that John uses the expression “title” (Greek: titulum). “Now Pilate wrote a title and put it on the cross.”(KJV) A slave being offered for sale could have a board or a sign (titulum) on his neck with his qualities written on it. It is remarkable that John has the most complete superscription which is in accordance with his use of the word title. But also John doesn’t claim to be complete. 

Living Pattern

Jesus was not the first who was to be crucified in Jerusalem by the Romans and he was not the last. In other words there were certainly boards in use to meet the need of a clear presentation in three languages (Living Pattern). The best way was to make three columns as follows:

Zè hou
Mèlèk Hajehoudim
Hic est
Rex Iudaeorum
Houtos estin
Hò Nazõraios
Hò Basileus tõn Ioudaiõn

In English:
This is
Of Nazareth
The King of the Jews
The living pattern of this type of boards in use for crucifixions in Jerusalem seems to be underlined by Mark and Luke. Giving a part of the writing they speak of “the inscription of the charge” or of “an inscription” which seems to suggest that they give the full writing. But looking to the overview we see that there are at least four inscriptions below each other in each language.
With this in mind we immediately see that Mark as well as Luke are definitely correct reporting the information on the cross. Conclusion:

No Bible Contradiction

Additional remarks

1. A more accurate translation for Luke would be:
38 Now there was also an inscription above Him, “ THE KING OF THE JEWS,” (is) this.
“(is) this” after the quote and not being part of the quote suggests that Luke refers to the first inscription “Houtos estin” (This is), that in common parlance certainly had a negative connotation of an accusing finger to the guilty one in this context.

2. Why seem the apostles to be so careless in their reports concerning the writing on the cross? The cross was certainly a most vital part of the Christian belief from the beginning. It’s all the work of the stenographers (See: Jesus’ Stenographers). They made specific observations which were used in their reports. Dogmatism is not the way to explain the detailed aspects of the gospel reports. We have to face the differences honestly. There will always be an adequate answer as these early writers were inspired by the Holy Spirit. This Spirit wants to inspire us now with these reports. Therefore it is no hobby to answer the questions; it is a privilege and a comfort.